Frenchman Romain Bardet won the 12th stage of the Tour de France finishing over the top of Fabio Aru on the final climb to the finish line.
Italian Aru claimed the overall leader's yellow jersey as previous race leader Chris Froome could not sustain the pace in the final few hundred metres up the steep climb to the summit finish.
Aru attacked hard with a few hundred metres to go and Froome initially went with him before dropping 20 seconds back at the line.
Overall, Aru leads Froome by six seconds and Romain Bardet by 25.
"It's a great joy, I had good legs but I was patient, the team has never been so strong; we are a real factor in the race, now we have to do our best in the final part," Romain Bardet said.
"I dedicate this jersey to my teammates, who have been doing everything to help me," said Aru.
New Zealand's George Bennett climbed from 10th to 9th overall.