Geraint Thomas admitted he felt "weak" after the unforgiving slopes of the Tourmalet dealt a blow to his Tour de France hopes.

The defending champion was the last and most surprising contender to lose contact with the front group on the highest paved pass in the Pyrenees, falling away one kilometre from the finish of this 117.5km stage 14 before Thibaut Pinot took victory and Julian Alaphilippe finished second to extend his lead in yellow.

Everybody was waiting to see whether Alaphilippe would wilt in the high altitude. Instead, Team Ineos owner Sir Jim Ratcliffe watched from the team car as the Welshman cracked instead, losing 36 seconds on the road and more in bonuses.

"Not the best day," Thomas said. "I just didn't feel quite on it from the start. I was quite weak. At the end I knew I just had to pace it. I didn't really attempt to follow when they kicked.

"I just thought I should ride my own pace rather than follow them and blow up on the steepest bit at the end. It's disappointing. I just tried to limit the damage."

Asked if he was unwell, the Team Ineos rider said: "We will see in the next few days. From the start I just didn't feel great. There's still a lot to come."

French fans were in raptures as Pinot rode away to take his third career stage win and Alaphilippe crossed the line six seconds later in second to extend his lead over Thomas to two minutes two seconds.

Deceuninck-Quick Step's Alaphilippe had already defied predictions to pull out time on Thomas in Friday's time trial, but this was an even bigger surprise.

"I knew that a yellow jersey can change you," Astana boss Alexandre Vinokourov said after Friday's stage, "but I didn't know it could make you fly."

Whether or not the 27-year-old, who has never finished in the top 30 of a Grand Tour before, can actually keep it up remains to be seen, but either way Thomas' other rivals for yellow will have been encouraged by what they saw here.

Steven Kruijsiwjk's Jumbo-Visma team looked strong as he rode to third on the stage and now third overall, cutting his deficit to Thomas to just 12 seconds.

Bora-Hansgrohe's Emanuel Buchmann and Groupama-FDJ's Pinot are now 70 seconds behind the Team Ineos man in fifth and sixth respectively.

The good news for Ineos on the day was that Egan Bernal, fourth overall, reclaimed the white jersey as Alaphilippe's team-mate Enric Mas was one of half a dozen contenders to fall away.

Bernal had ridden away as Thomas was going back, but the 22-year-old said he was prepared to wait.

"I know that the defending champion is my team-mate," the Colombian said. "I won't go against the instructions of my team. If I'm asked to help, I will do. If I'm given freedom, I'll try to make the best of it."

One by one contenders had gone by the wayside on the Tourmalet, starting with Adam Yates, who would ship more than six minutes as his hopes ended. Irishman Dan Martin went next, losing more than five minutes, before Rigoberto Uran, Richie Porte and Nairo Quintana followed.

Romain Bardet had not even made it to the Tourmalet, cracking in spectacular style on the Col du Soulor to lose more than 20 minutes, such was the unforgiving nature of the day.

French fans could celebrate, however, as Pinot gained a measure of revenge for the time he lost in the crosswinds on stage 10.

"It's magnificent, exceptional, magical," said the 29-year-old, who admitted he had been "angry" since being caught out on the rode to Albi.

"Today was the first real mountain stage, the first test. I've been thinking about this stage since the start of the Tour. This was one that I really wanted.

"The Tourmalet is mythical! I'm happy, it's the kind of racing I love."

Thomas, clearly deflated at the finish line, was left with rather different sensations, but Ineos sporting director Nico Portal insisted there was no need to panic.

"We're still OK for the GC," he said. "Geraint didn't have a great last couple of kilometres but he kept on riding. He lost 30 seconds. It's not a big blow but sometimes you can have a bad day and hopefully that's his bad day...

"On the radio he said he was struggling but his microphone wasn't working anyway. He's struggled and lost 30 seconds but it's not such a big deal."