PEYRAGUDES, France (AP) For his three previous victories at the Tour de France, Chris Froome took advantage of the first big mountain stage to deliver the decisive blow.
On Thursday, that tried and trusted strategy never got going, and he surrendered the overall race lead to Fabio Aru.
With its mountain top finish, the hugely demanding first stage in the Pyrenees looked like the perfect setting for his Sky Team to stamp its authority on the race, and to help Froome increase his lead in the general classification.
Until the final 350 meters of the 214.5-kilometer (133 miles) marathon through six grueling ascents in the Pyrenees, the well-oiled Sky machine had everything under control.
Froome's teammates had set a fast tempo that prevented others from attacking - a tactic that prepared the ground for Froome's expected assault in the steep final section leading to the finish in the ski station of Peyragudes.
Froome's move never came.
Not only was he unable to attack, the British rider also cracked during the climb. Frenchman Romain Bardet won Stage 12 ahead of Rigoberto Uran and Aru, who seized the lead from Froome by six seconds.
Bardet is third overall, 25 seconds off the pace. Uran was handed a 20-second penalty for accepting a water bottle in the last five kilometers, which is not allowed, and lies in fourth place overall, 55 seconds back.
''My teammates did such an amazing job,'' Froome said. ''I didn't have the legs at the end to finish it off. Simple as that. No excuses.''
When Aru launched his attack in the final few hundred meters, Froome was only able to follow the Astana team leader for a few bike lengths before he cracked. He ended up crossing the line in seventh place, 22 seconds behind Bardet.
Bidding to become the first Frenchman to win the Tour since Bernard Hinault in 1985, Bardet was the strongest in the brutal incline and described his third stage win on the Tour as ''an immense joy.''
He said he had visited the ski station with his parents to scout out the final climb.
''I knew it could suit me,'' he said. ''I was patient. I made the difference on the final hill. There was not much to do before that with the wind and the Sky train.''
Aru had trailed Froome by 18 seconds at the start of the stage.
''It's one of the most beautiful things that can happen to you in life, wearing the yellow jersey,'' said Aru. ''Clearly, it won't be easy to defend it. There are still nine more stages, we'll do our best.''
The final of the six ascents on the menu of the 214.5 kilometers (133 miles) stage between Pau and the ski station was too difficult for Froome, who had worn the yellow jersey over the previous seven stages.
He was grimacing with the effort, his arms glistening with sweat, as he wrestled his bike up the super-steep climb that was used a location for the 1997 James Bond movie ''Tomorrow Never Dies.''
Froome zig-zagged his bike across the tarmac as he tried to cope with a gradient so steep that it seemed to glue his wheels to the road.
The only yellow item he wore after the finish was the small ring in his nose to help him breathe.
''I did my utmost at the end. But I didn't have the legs to follow,'' he said.
Froome has only a few hours to bounce back before Friday's short but hard stage to Foix, which features three Category 1 climbs - the second-hardest difficulty rating. Now that Froome has shown signs of weakness, the attacks could come right from the start as his rivals look to build on the momentum.
''Aru attacked a bit too early to win the stage, but he got the jersey and saw that Froome can be beaten. He'll definitely try some more,'' Astana manager Alexandre Vinokourov said. ''Sky is very strong, but today Froome took a hit and his team could be demoralized. Let's hope our guys find more motivation.''
Rain was falling as the peloton started the stage in Pau, before a breakaway of 12 riders gained a lead of more than six minutes on some fairly flat sections of the course.
Froome's teammates rode at the front with Aru's squad just behind, but showed no interest in reducing the gap with the breakaways.
Sky stepped up the tempo in the first really difficult ascent, the Col de Mente, where Spanish great Luis Ocana crashed out in a downhill section in 1971 while wearing the yellow jersey. The twisting and punishing Port de Bales, a narrow, 11.7-kilometer climb at an average gradient of 7.7 percent - rated as `beyond a category' because of its difficulty - took a heavy toll on the lead riders. The breakaway group split up as Stephen Cummings launched a solo offensive.
Aru's teammate Jakob Fuglsang, who broke two bones in a crash during Wednesday's stage, struggled at the back and dropped out of contention after starting the day in fifth place overall.
Cummings had a two-minute lead at the top of Port de Bales and went all out in the descent as the fog broke and the weather picked up. Froome, Aru and Mikel Nieve misjudged a turn in the downhill but the race leader and his rival pushed hard on the brakes to avoid a crash. Nieve went straight onto the grass between lorries and camping caravans.
It was nothing more than a scare for Froome, who had three teammates by his side to tackle the two final climbs, the Peyresourde and the Peyragudes ascent.
Nairo Quintana was dropped in the Peyresourde and, with no teammate to bring him back, saw his hopes of winning the Tour vanish. Cummings was then caught with 8 kilometers left, lining up a dramatic finale.