Finally, a crack in the armour. After 14 extraordinary days, Julian Alaphilippe showed he was human on the Prat d'Albis on Sunday.
For the first time in this sensational Tour de France, we saw Alaphilppe dropping from the back of a group rather than accelerating off the front of it. He was unable to live with the relentless forcing of pace from his compatriot Thibaut Pinot and even conceded ground to second-placed Geraint Thomas.
This, however, was no crashing back down to earth. Alaphilippe placed 11th on the stage with a cast of big-name GC riders in his wake and the yellow jersey still on his shoulders. The damage to Pinot was 1:16 but that to Thomas was a modest 27 seconds.
The day after an hors-categorie summit finish on the Tourmalet, it was a performance that was arguably above and beyond what he and we might have predicted a fortnight ago. But then again, our expectations of Alaphilippe have been completely rewritten at this Tour.
Nevertheless, it's hard to escape the feeling that, 24 hours after his watershed second-place on the Tourmalet, Sunday's stage signified a new turning point. His extraordinary efforts over the past two weeks are beginning to add up and there are still three gruelling days in the Alps between here and Paris.
"I expected it to be difficult. I'm not disappointed, I'm just completely spent. It's not a surprise for me to crack against the best climbers, especially after yesterday's stage, where I really went deep into my reserves," Alaphilippe said at the top of the mountain.
"I'm cooked. It was a stage that caused a lot of damage. It wasn't one thing in particular that put me in difficulty – it's more the last two weeks, all I've done, all I've given… I'm starting to pay for it."
For a long way up the Prat d'Albis, it looked like Alaphilippe was on his way to shocking us again, and installing himself as an even stronger candidate to overall victory. When Pinot attacked with just over 6km to go, he was one of only three riders able to respond - along with Egan Bernal and Emmanuel Buchmann – while Thomas and Steven Kruijswijk slipped back.
However, a kilometre later, Alaphilppe could no longer hold Pinot's pace. He dropped back and hung in with Thomas and Kruijswijk, but then started to struggle when the 2018 champion attacked with 2km to go. From there, he was on his own, grimacing and fighting with the bike, his previous effervescence replaced with pure suffering.
Was it a mistake to try and follow Pinot's initial surge?
"We can't always do the race again, but at that point, when he attacked, I felt good - it's only later that I didn't feel so good," Alaphilippe explained.
"I'm not used to defending the lead in a stage race and I'm learning from my mistakes, but I don't think that today I made a mistake. It's not a surprise for me to have lost some time, I had stiff legs after yesterday's stage. It's mission accomplished for me. In the bus this morning, the goal was to retain the yellow jersey. I'm still here, the dream goes on. I'm not carried away by having the yellow jersey, I'm just enjoying it, as usual."
So, what happens now? As we've become accustomed with Alaphilippe, it's hard to predict.
He didn't fully crack, but Prat d'Albis suggested the start of a decline. Then again, he still leads the Tour by more than a minute-and-a-half. Thomas is at 1:35 and Kruijswijk 1:47, while the rapidly advancing Pinot is at 1:50.
Monday's rest day in Nîmes is followed by two days off as far as the battle for yellow is concerned, but there's a huge sting in the tail of this Tour in the form of three big Alpine stages, two summit finishes, and six climbs that break the 2000m altitude barrier.
"It's no a surprise I have suddenly have the pedigree of a potential winner, but I remain realistic on the gradients.
"We have hope. I'm aware that it will be difficult. It's not a surprise I'm starting to struggle. I haven't lost form today, I have just lost a bit of time. I didn't have the ambition to win the Tour and today nothing changes for me.
"On the other hand, it changes things for Thibaut Pinot, after what he did yesterday and today, this whole week suit him really and if I lose the yellow jersey, I would like Thibaut Pinot to be the next one to take it."