The riders are signing on in the tiny village of Trie-sur-Baise. they face 171km in the rolling countryside before the finish in Pau.
Tom Dumoulin gets a huge cheer as he signs on. He's seen as the biggest challenge to Team Sky's dominance.
Team Sky are next on stage. They won the team prize yesterday and so get a special banana prize.
Geraint Thomas seems as cool and collected as ever in the leader's yellow jersey.
Thomas said:
"It was a good day, it was a tough day but fortunately I was feeling good and I was able to respond to the attacks and in the end I consolidated my lead."
Thomas kept his feet on the ground.
"We've still got today and there are still two more big days, it's not over yet."
Thomas did admit he is now Team Sky's protected leader.
"We always said from the start that the road would decide things because you never know what can happen.
"Hopefully its a sprint today and then we'll worry about tomorrow."
Lawson Craddock of EF Drapac signs on for another day. He is still in the tour, despite crashing hard on stage 1 and suffering a micro-fracture in his shoulder.
His bravery has helped raised over 150,000 dollars for his local velodrome in Houston.
Peter Sagan has yet to sign on but we've been told he will race on despite his high-speed crash yesterday.
Julian Alaphilippe signs on next. He's covered in polka-dots as leader of the climber's competition.
He said he hopes to recover from his efforts during today's stage so to be ready to defend the polka-dot jersey on Friday.
All the talk at the start is if the sprinters will try and be able to stop a break stating away today.
So many sprinters are out of the Tour and others are tired, so the attackers seem to have a chance of a final shot at victory today.
The riders have signed and lined up. We're seven minutes from the roll out.
Here's Sagan.
He's wrapped in bandages but races on.
"I'll hope I'll be okay, we'll see during the stage. Tomorrow will be harder," Sagan said.
To read about Sagan's crash, click here.
Sagan and the other jersey wearers move to the front of the peloton for the roll out.
Quintana is also there as yesterday's stage winner. He seems a lot happier now he has won a stage and made sense of his Tour.
This is the overall classification as the riders prepare to roll out. Thomas leads by almost two minutes now.
1 Geraint Thomas (GBr) Team Sky 70:34:11 2 Tom Dumoulin (Ned) Team Sunweb 0:01:59 3 Chris Froome (GBr) Team Sky 0:02:31 4 Primoz Roglic (Slo) LottoNL-Jumbo 0:02:47 5 Nairo Quintana (Col) Movistar Team 0:03:30 6 Steven Kruijswijk (Ned) LottoNL-Jumbo 0:04:19 7 Mikel Landa (Spa) Movistar Team 0:04:34 8 Romain Bardet (Fra) AG2R La Mondiale 0:05:13 9 Daniel Martin (Irl) UAE Team Emirates 0:06:33 10 Jakob Fuglsang (Den) Astana Pro Team 0:09:31
To catch up on all the racing and news from Wednesday's 65km stage in the Pyrenees, click here.
The riders have left the start area and are riding to the official start 2.9km out of town.
We can already see the attackers gathering behind the red race director's car from the CN blimp.
It's hot out there, close to 30C, with riders putting small bags of ice under the neck of their jersey to try to stay cool.
There are even reports of the road surface meting in the heat.
Olivier Le Gac has suffered a puncture and so the race director extends the neutralised sector a moment.
Allez! Christian Prudhomme waves the flag and they're off!
169km remaining from 171km
And we have the first attacks. The peloton is lined out.
The country roads are slightly downhill for 15km and so it is a very fast start.
The early attackers are: Terpstra, Van Keirsbulck, Hayman, Durbridge and Boudat.
Mitchelton-Scott has two riders in there and are giving it big licks.
164km remaining from 171km
There is a big group chasing the five.
Bora, Groupama-FDJ and Team Emirates have lead the chase, with the peloton closing down the chasers.
The five lead by 15 seconds and are trying to snap the elastic to the peloton.
This is the map of the 171km stage. The route rolls through the Gers, Hautes-Pyrenees, Landes and Pyrenees-Atlantique departments of southern France.
It is a day of sunflowers, vines and sunshine.
157km remaining from 171km
The peloton refuses to let the five go away, despite some big licks on the front from Terpstra, Hayman and Durbridge.
The gap is rising. Has the peloton let them go?
The peloton reacts, with several counter-attacks off the front.
Also in the attack are Guillaume Van Keirsbulck (Wanty) and Thomas Boudat (Direct Energie).
152km remaining from 171km
The five lead by 20 seconds but they are being hunted down.
This is a screen grab image of the attackers.
And this is the peloton chasing hard.
Marcus Burghardt suffers a rear flat but tries to ride along on the tyre till his Bora car arrives.
145km remaining from 171km
Steady boys! The peloton has eased up and spread across the road.
We seem to have the early break of the day.
143km remaining from 171km
The gap is up to 1:20 as the peloton hit a flat, straight road.
139km remaining from 171km
The Groupama-FDJ team has taken up the chase, riding steady to keep the break under control in the hope Demare can win the sprint.
Speaking before the start, Chris Froome has confirmed that he and the team will ride 100% for Geraint Thomas.
"I'll do my maximum to finish on the podium but we're riding all for Geraint now," Froome said.
Froome insisted that he was not too disappointed to miss out on the chance of a fifth Tour de France.
"I won the Tour last year, then the Vuelta, then the Giro and this year i'm on the podium at the Tour. That's a lot. I'm on the podium and I'm happy with what I've done. If Geraint wins that'd be great."
Emirates and Bora-Hansgrohe are helping Groupama with the chase of the break.
The peloton refuses to let the five open a big gap. Their lead is a down to 1:00.
We see the usual picture of Sky leading the peloton, followed by Sunweb. What is unusual is the inclusion of a Movistar rider.
Team Sky refuses to admit that they have now won the Tour -- tomorrow's final mountain stage could be crucial. Read about it here.
122km remaining from 171km
With 122 km to go, the gap has "jumped" all the way to 1:25.
Yesterday's short but highly mountainous stage was one of those "You might now win the race here, but you sure can lose it." That turned out to be true for Romain Bardet (AG2R), who finished 2:35 down and now has to face he has virtually no chance of repeating his podium appearance of the last two years.
Speaking of Bardet, he is coming back to the field from the team cars.
The leaders are approaching the first climb of the day, the cat.4 Cote de Madiran.
UAE Emirates and Groupama-FDJ have now sent several riders each to the head of the peloton.
Terpstra rolls over the line first for the mountain ranking, but we can't say that there was any interest or competition in picking up the point.
110km remaining from 171km
The exact gap bounces around within a few seconds, but isn't changing dramatically, currently at 1:18. The sprinters' teams (and yes, there really are still a few sprinters in the race) refuse to let a break get away and stay away.
AS the gap has dropped to just under a minute, two Trek riders and an EF rider have jumped from teh field. There is no effort to chase them.
The two Trek rides are Stuyven and Gogl, with Van Marcke.
A crash in the field takes down a handful of riders, including Nario Quintana, yesterday's stage winner. He seems to have some problems with shoulder, hand or arm, but is of course on his way back up to the field.
Yates was also involved in that crash, but is ok. Quintana seems to have problem with a finger.
Gogl drops out of the chase group.
Quintana also has a blood-smeared left elbow.
Van Keirsbulck picks up 20 points at the intermediate sprint. Back in the field, Degenkolb wins the sprint of the bunch.
Quintana at the medical car, getting that left arm cleaned up and looked at.
89km remaining from 171km
Quintana is now back in the peloton, no doubt in a pain after that surprise spill.
The Movistar team posted this screen grab shot of Quintana getting treatment on his left elbow.
85km remaining from 171km
Hayman flats in the break. He's on disc brakes and so it takes the mechanic a fair bit longer to change the wheel.
His day out front could be over.
84km remaining from 171km
The break leads the peloton by 2:10 as they grab their musettes and understand what is for lunch.
No fatty duck cassoulet for them.
Hayman is back up front. That was quick! Fortunately the break is on a slight climb and so the speed is lower.
The remaining 83km is on rolling roads before a fast finish into Pau.
The peloton also hits the feed zone, with riders taking their musettes.
80km remaining from 171km
These are the five riders in the break of the day.
This southern area of France is famous for its food and wine.
According to the daily Associated Press Taste the Tour blog, the local dish in Pau is poule au pot.
"This traditional French dinner was one of Henri IV’s favorite meals. Literally “hen in a pot,” it’s a whole hen stuffed with minced pork and veal, breadcrumbs and an egg. It should be cooked in boiling water with carrots, turnips, rutabagas, celery and onions," AP explains.
Pau is the birthplace of 16th-century king Henri IV.
Pau will be visited for the 70th time this year after hosting the race for the first time in 1930.
The city has a special cycling champions open-air museum on the site of the former velodrome.
71km remaining from 171km
The riders pass the Eugeni-les-Bains spa resort but there is no time to take the waters for the peloton.
68km remaining from 171km
The gap of the five is at 1:30, which equals 1.1km on the road. The break and the peloton are playing cat and mouse at the moment. Nobody is going 100%, saving their strength for the high-speed finale.
Romain Bardet is riding in the depth of the peloton. He had a difficult day yesterday in the mountains but talked about his race post-race.
The Cofidis team is also helping with the chase of the break. With Nacer Bouhanni not selected for the Tour, they are perhaps hoping Christophe Laporte can win.
The late climb of Cote d'Anos with 19km to go could help eliminate some sprinters if the race explodes.
Cyclingnews Editor Daniel Benson caught up with race leader Geraint Thomas at the start.
The Welshman insisted that today's sprint stage is not an 'easy' day for the peloton.
"It's never easy and there's always something that happens. You've got to stay on the ball but hopefully it's easier than the last few days," Thomas said.
Thomas was more relaxed at the start after extending his overall lead to 1:59 on Tom Dumoulin and distancing teammate Chris Froome, who is now at 2:31.
"Yesterday was a good day and a big step. I'm not thinking about it too much or getting carried away," Thomas said.
"I'm really proud of that performance yesterday. It was great for the morale and the confidence within the team. There are two more days and hopefully we can stay on the ball."
He added:
"Yesterday was probably a bigger performance for me in terms of GC than the two stage wins, I think."
"Just because it was the last summit finish of the race and others wanted to try and gain time if they could. I gained time on everyone else, other than Quintana, and that was really encouraging."
Thomas knows that he faces one final mountain stage and then Saturday's key time trial stage before the parade stage into Paris.
"One more mountain stage, and we're going to get attacked on that last climb. Hopefully I can respond to anything. Then it's the TT. I'm trying not to look too far ahead. I've just got to look at each day at a time," Thomas said.
54km remaining from 171km
The gaps stays at 1:20 as Groupama, UAE and Cofidis swap off at the front.
The crowds are huge along the roads today despite he high temperatures.
50km remaining from 171km
The UAE is riding to control the break in the hope that European champion Alexander Kristoff can win an eventual sprint.
Kristoff knows he has just two chances of victory this year.
"It's just today and the Champs Elysees left for me. I hope to be first over the line but there are still many fast guys here. Not as many, but still a few," Kristoff told CN.
"I feel okay after the mountains, but we have to make sure there's no mistakes. We don't have a super leadout but I still have a few guys, so I hope to have a good position and then try and sprint for the win."
Kristoff finished second in Valence behind Peter Sagan and was fourth in two other sprints.
His last victory was at the GP du canton d'Argovie in Switzerland in early June.
45km remaining from 171km
The peloton rolls through the French countryside as the kilometres tick down.
The late climb comes 19km from the finish and so we can expect the speed to rise soon.
The GC riders are enjoying a quiet day in the peloton before Friday's final mountain stage.
Adam Yates dropped out of the GC in the Alps and is targeting stages. Friday is his last chance.
"Today is pretty flat. There will be a break so I'll just try and save my energy for tomorrow," the Mitchelton-Scott told CN at the start.
"Then we have the last roll of the dice for tomorrow's final mountain stage. I had another go yesterday but there were a couple of guys really going for it, but I just didn't have the legs. That's how it goes."
Peter Sagan had a nasty crash yesterday but he’s still racing today, even he is wrapped in bandages like a mummy and in pain.
He is focused on making it to Paris to win his sixth green jersey.
“Considering how bad the crash was, my condition could have been worse", Sagan told France Television on the start line today.
"My back is full of bruises. It’s going to be hard. My only goal is to complete the race.”
We will see if that is the case very soon. Sagan has already won three stages this year.
32km remaining from 171km
The break is upping the chase now and so are the five breakaways.
It's race on!
Arnaud Demare is a big favourite for the expected sprint today.
He finished just inside the time limit in the Pyrenees and was forced to defend himself against accusations from fellow sprinter Andre Greipel. The German later apologised.
Laporte suffers an untimely flat but gets a quick change and is chasing hard to get back up to the front.
21km remaining from 171km
It's time for the Cote d'Anos. this should shake up the race.
Indeed the 5 attackers are only 20 seconds clear now.
21km remaining from 171km
It's time for the Cote d'Anos. this should shake up the race.
Indeed the 5 attackers are only 20 seconds clear now.
19km remaining from 171km
Terpstra leads onto the climb but the peloton is coming up fast.
Here we go! Simon Clarke ups the speed and a group goes off the front of the peloton.
17km remaining from 171km
The peloton is lined out behind them as they reach the top of the hill.
Jack Bauer is there for Mitchelton-Scott and tries to push on.
But the peloton is coming.
Gruppo compatto.
Team Sky close it down just before a right turn.
Bora is also moving up and perhaps preparing to work for Sagan today despite his crash injuries.
12km remaining from 171km
Groupama have taken over the pace at the head of the peloton for Demare. They want a fast but attack-free run-in to Pau.
Bora is also leading the peloton. They know the finale is technical and so suits Sagan's bike handling skills.
7km remaining from 171km
Team Sky is also up front, protecting Thomas and Froome.
The peloton is lined out on the main road into Pau.
4km remaining from 171km
Bora has three riders on the front, with Sagan tucked in their slipstream.
There are several pinch pints and a final left turn before the final kilometre.
EF Drapac also has a small train going for Scully.
Trek are riding for Degenkolb.
3km remaining from 171km
A shuffle almost sparks a crash. This is fast.
Sagan is on Laporte's wheel. Where is Demare?
1km remaining from 171km
Last km!!!
They sweep through the last corner. Sprint!
Cofidis lead it out!
Demare kicks!
He stayed on the barriers and won it well.
Demare moved to the centre of the road but held off Laporte and Kristoff.
Demare distanced the other sprinters when he opened up. Kristoff was several lengths behind at the line.
Sagan was only eighth today.
This is the top ten on the stage.
1 Arnaud Demare (Fra) Groupama-FDJ 3:46:50 2 Christophe Laporte (Fra) Cofidis, Solutions Credits 3 Alexander Kristoff (Nor) UAE Team Emirates 4 Edvald Boasson Hagen (Nor) Dimension Data 5 Sonny Colbrelli (Ita) Bahrain-Merida 6 Maximiliano Richeze (Arg) Quick-Step Floors 7 John Degenkolb (Ger) Trek-Segafredo 8 Peter Sagan (Svk) Bora-Hansgrohe 9 Taylor Phinney (USA) EF Education First-Drapac p/b Cannondale 10 Timothy Dupont (Bel) Wanty-Groupe Gobert
Geraint Thomas finished in the peloton and so remains in yellow.
This is the GC after stage 18.
1 Geraint Thomas (GBr) Team Sky 74:21:01 2 Tom Dumoulin (Ned) Team Sunweb 0:01:59 3 Chris Froome (GBr) Team Sky 0:02:31 4 Primoz Roglic (Slo) LottoNL-Jumbo 0:02:47 5 Nairo Quintana (Col) Movistar Team 0:03:30 6 Steven Kruijswijk (Ned) LottoNL-Jumbo 0:04:19 7 Mikel Landa (Spa) Movistar Team 0:04:34 8 Romain Bardet (Fra) AG2R La Mondiale 0:05:13 9 Daniel Martin (Irl) UAE Team Emirates 0:06:33 10 Jakob Fuglsang (Den) Astana Pro Team 0:09:31.
Demare was out of position before the final kilometre but got back on Jacopo Guarnieri's back wheel, who produced a perfect lead out.
Laporte waved his arm in protest at Demare moving to the centre of the road but the race jury is unlikely to overturn the result.
Demare was delighted to win after suffering the Pyrenees.
"This is what I was thinking about during the hard moments in the mountains. My team was super, and this is a nice reward for us," he said.
Asked about Greipel, Demare replied.
"I can thank him because I thought of him a lot today…" he said.
"It’s not my philosophy of cycling to do that. I worked hard before the Tour to prepare for the mountains. It wasn’t easy to get through them, and I’m very pleased to win today."
Demare waves and smiles as he climbs on the podium. It's a big day for the French rider after suffering so much to get this far.
Geraint Thomas pulls on the yellow jersey again. He enjoyed a quiet day in the peloton today.
His big day comes tomorrow in the Pyrenees.
There is a quiet applause but no boos for Thomas on the podium.
This is the first shot of Demare winning the stage.
Demare's win has boosted his moral for the final sprint in Paris after he suffered so much in the Alps and Pyrenees.
Of course he has to survive Friday's final mountain stage if he wants to get to Paris.
"I’ve been through some difficult moments but I really wanted to make it to the final sprints and play my cards. I always believed in myself and my chances of winning in this Tour," he said.
"Winning today, before the final chance on the Champs Elysees is great for my motivation. This is for my wife, my family and my friends."
"It was a fast sprint after a fast stage. I was well-placed thanks to Jacopo Guarnieri and believed I could win. The team was perfect in the way they set me up."
"People who know me, know how hard I trained for the Tour de France and this goal. That’s why I’m so happy today."
Geraint Thomas was happy to survive the hot day in the south of France.
"It was a solid start. It definitely wasn’t an easy day. We were on the pedals all day, and it was a hot day which was tough, and a fast final as well. It was stressful but I’m happy to get through it," he said after pulling on a clean yellow jersey.
The Team Sky leader is sticking to his daily routine.
"I just try to take it day by day. Obviously there is one more big day, and we are expecting a lot of attacks. There is a lot of climbing, it’s going to be a hard day, but we’ve ridden really well as a team so far so hopefully we can keep that going," he said, expecting attacks on the climbs and even descents.
"We’re expecting the worst, really - guys trying to go in the early break, attacks on the Tourmalet, and obviously attacks on the final climb and descent. We’re just going to be really ultra vigilant and stay on our toes and keep doing what we’ve been doing."
"Hopefully they can guide me through it and I can stay strong in the wheels and we’ll see how it goes."
Demare let out his emotions after winning the stage.
There was some concern at the Movistar bus about Nairo Quintana after his early crash.
He lost some skin and went down hard.
Nairo Quintana was angry to be in pain.
“It is unfortunate to have suffered this fall; one way or another, it seems I’m always a little fu*cked up. I have bruises on my ankle, shoulder and also on a finger that already hurt me at yesterday’s stage," he said.
"The race doctors put gauze on me, but until I clean up, take a shower and see what the team doctors say, I will not know a hundred percent if it is of little importance. We hope to be able to recover well, do a good job with the physios of the team and try to perform as well as possible tomorrow."
This was the moment Quintana picked himself up after his crash.
To see more of our great photos from today's stage and to read our full report, click here.
This image shows Demare after he opened up his sprint.
The south of France near Pau offers some stunning postcard shots with sunflowers and vines.
There has been lots of talk of rivalry in Team Sky but this shot shows both Thomas and Froome in a good mood.
Stay with our live coverage as we publish rider reactions and interviews from our reporters in Pau.
We'll have full live coverage of Friday's stage 19 through the Pyrenees. Join us to find out if anyone can challenge Geraint Thomas and Team Sky.
