The travails of Nairo Quintana may have held the greatest significance as Chris Froome took a huge step towards a third Tour de France title on Wednesday's stage 17, but it was a bad day for another of his rivals, Bauke Mollema, that saw his lead stretch out to nearly two-and-a-half minutes.
Though there was always the feeling that Quintana represented the biggest threat to Froome's stranglehold on the race going into the Alpine denouement, an attack on Mont Ventoux and a strong time trial had seen Mollema emerge, on paper at least, as the Briton's closest challenger.
However, on stage 17, the day after the second rest-day and the first in a quartet of decisive mountain stages, cracks appeared in the Dutchman's armoury as he lost contact with the yellow jersey group on the final kilometers of climb to the Finhaut-Emosson dam in Switzerland.
"I didn't have such good legs today," Mollema told a huddle of journalists outside his team bus, revealing he was in trouble well before Richie Porte's attack saw him distanced.
"I already felt it on the second last climb a bit and then on the last climb, when the attacks started, I couldn't follow. I didn't have the legs I had last week. That's a pity but in the last 2k I kept fighting until the finish line not to lose too much time.
"In the morning I still felt good but the first 140 kilometres were quite flat and it's hard to stay how you feel. But on the second last climb already I didn't feel so good. You know it was an important day today and the last one was really steep."
Mollema remains second overall but lost 40 seconds to Froome – who went with Porte – and now finds himself 2:27 down, also having conceded 22 seconds to third-placed Adam Yates and 12 to Quintana in fourth.
That is no disaster, and he remains on course for his best-ever Grand Tour finish, but he will have to hope today is not a sign of the direction in which his Tour is heading. The concern will be that he's been here before, having found himself second on the second rest-day in 2013, only to fade and fall to sixth in the final week.
Mollema insisted it was "just a bad day," that "it could have been worse," and that "hopefully the next days will be better".
Guercilena: The top five was always our goal
His team manager, Luca Guercilena, agreed that today wasn't a hugely significant blow and, though he can't see how Froome can be beaten, voiced his confidence in Mollema to record his best-ever Tour finish – his previous best having been sixth in 2013.
"He lost a few seconds too many but if this was our worst day, we'd settle for that," the Italian told Cyclingnews after Mollema had had his say. "The top five was always our goal and we're still second in the third week. We'll hang in there and see what we can do in the days to come.
"Up to today he's always been very solid in his performances. Today he suffered a bit in that last kilometre of real climbing but as soon as the road flattened out a bit, he made up some ground, but it's clear that the gaps were made. But we're still satisfied. We're still in the game and we're seeing that everybody is having difficult moments."
Mollema roared into second place on the stage 13 time trial in the Ardèche, and he'll be hoping to make similar gains on tomorrow's stage 18 time trial – an exclusively uphill 17km test in Megève, though without steep gradients the whole way.
"For Bauke, this is a good time trial – better than a pure mountain time trial," said Guercilena, whose thoughts must also turn to the finals two mountain road stages, where he struggles to see a way past Froome.
"From what we saw today, I see it as being difficult [to beat Froome]. The rivals change but he's always there," he said.
"The rhythm that Sky has laid down is so high that even the riders who attack are only gaining 100 metres. It's very hard for an attacker to stay clear. Today he gave another show of great strength. But maybe even he'll have a difficult day, like all of the others have had."