LA PLANCHE DES BELLES FILLES SKI STATION, France – After a severe crash on a steep descent, Spanish cyclist Alberto Contador of the Tinkoff-Saxo team abandoned the Tour de France in tears Monday.

Contador, a two-time Tour champion, and the defending champion, Britain’s Chris Froome of Team Sky, were the two overwhelming favorites to win this year. Both of them have quit the race after crashes.

Contador broke his leg and Astana rider Vincenzo Nibali regained the overall leader’s yellow jersey by winning the 10th stage of the 21-stage event.

Nibali witnessed the crash while riding near Contador at more than 35 mph.

“The asphalt was not in good condition,” he said. “He was behind me, but then passed me and three seconds later, he fell off in front of me. It was spectacular.”

The crash wrecked Contador’s bike, and doctors had to bandage his right knee, which was bleeding. Mounting a new bike and wearing a new shoe, Contador was shepherded by five teammates. But after riding about 9 miles along a foggy stretch of road, Contador climbed into a team car.

Bjarne Riis, Tinkoff-Saxo manager, said Contador has a fractured tibia that will require surgery.

Nibali, who has won the Spanish Vuelta (2010) and Giro d’Italia (2013), has inherited the role of favorite.

Nibali covered 100.3 miles in the stage that started in Mulhouse in 4 hours, 27 minutes, 26 seconds, 15 seconds ahead of Frenchman Thibaut Pinot.

“This was the hardest stage I’ve ever done in a Grand Tour, with seven climbs and so many crashes,” said Nibali.

Nibali leads Australian Richie Porte, who took over Team Sky after Froome’s departure, by 2 minutes, 23 seconds in the overall race.

Nibali said he expected a battle with Contador in the 10th stage.

“I already had a good lead and I was ready to fight in a big duel with Alberto,” he said. “Crashes are part of the sport. I’ve crashed myself many times in the past, too. It’s a pity that the Tour has lost two major protagonists.”

According to his spokesman, Contador said he wasn’t exactly sure what caused the crash.

“He explained to me just a few minutes ago that he (hit) a stone or a hole in the road or something — and he crashed,” Contador spokesman Jacinto Vidarte said.