PLANCHER-LES-MINES, France -- Two-time champion Alberto Contador dropped out of the Tour de France on Monday after crashing during Stage 10, the second big withdrawal that blows the race wide open and ensures that cycling's greatest race will have a new champion this year.

The 31-year-old Spaniard with Tinkoff-Saxo Bank becomes the second big favorite to drop out this year after defending champion Chris Froome of Britain crashed out in Stage 5. Before the race began this year, Froome and Contador were seen as the top two favorites to possibly win this year.

In circumstances that a team spokesman could not immediately explain, Contador crashed about halfway through the 161.5-kilometer (100-mile) trek from Mulhouse to La Planche des Belles Filles featuring four steep Category 1 climbs in the eastern Vosges mountains, the toughest stage so far this year.

TV images showed thick streams of blood pouring from Contador's knee after the crash, his hip was scraped up, and the back of his jersey torn. Team director Bjarne Riis rushed over and bandaged the rider's right knee.

Contador then sat back down on grass bank and changed his left shoe as riders, weaved through the narrow gap between him and his bicycle. After several minutes, he got back in the saddle of a new bike, and three teammates who had dropped back escorted him to try to make up lost time as the peloton pulled away up the Col du Platzerwaswel mountain pass.

The Spaniard rode for about another half-hour, clearly in pain, and finally stopped, got off, wiped his eyes and climbed into a team car.

Contador began the stage in ninth place overall -- 4 minutes, 8 seconds back of race leader Tony Gallopin of France. The Spaniard's withdrawal vaults Vincenzo Nibali atop the list of likely winners this year. The Italian has won the Spanish Vuelta and Italian Giro, and wore the Tour leader's yellow jersey for seven days until Gallopin took it on Sunday.

Contador and Froome, along with 2010 Tour champion Andy Schleck, were the only three former Tour champions racing this year. Schleck dropped out before Stage 4 after sustaining an injury in yet another crash a day earlier., The last section of the final ascent up to Belles Filles features a punishing 20 percent gradient that could shake up the pack and give a clearer indication of the contenders for overall victory of the three-week race on the Champs-Elysees in Paris on July 27.