LA MONGIE, France — When the team of Geraint Thomas was in its pomp at the Tour de France, a time trial followed by a big mountain stage would have been playgrounds for Sky — now in new colors as Ineos — to take cycling’s greatest race by the scruff of the neck and leave everyone else fighting for second place.

Not this year.

Thomas, the defending champion, cracked on Saturday on the Tour’s first encounter with a climb to above 2,000 meters (6,500 feet), exposing weaknesses in a team that has won six Tours in the past seven years.

The time trial on Friday and the climb to the Tourmalet pass on Saturday seemed primed for Thomas to reel in Julian Alaphilippe, the yellow jersey holder from France who is setting the Tour alight with his punchy riding and determination to keep the race lead, filling French fans’ heads with dreams of a first homegrown winner since 1985.

But instead, Thomas has seen Alaphilippe only get further and further away. In two days, he has put 50 seconds of extra daylight between him and Thomas, a Welshman. His lead — up to 2 minutes 2 seconds — is becoming large enough to start realistically envisioning Alaphilippe in yellow in Paris next weekend as the first French winner since Bernard Hinault.