PRA LOUP, France (Reuters) - Chris Froome emerged unscathed from a treacherous 17th stage of the Tour de France on Wednesday, retaining his lead while Alberto Contador lost a lot of ground and Tejay van Garderen abandoned the race.
American Van Garderen, who was third overall at the start of the 161-km trek from Digne les Bains, pulled out because of sickness with the day's laurels going to German Simon Geschke after a brave solo raid.
"It's the most beautiful day of my life as a professional rider, it's surreal," said Geschke.
Spaniard Contador's hopes of achieving a rare Giro d'Italia/Tour double suffered another major knock when he lost touch with the group of top guns after crashing in the dangerous descent from the col d'Allos.
The Tinkoff-Saxo rider lost over two minutes on Froome and Colombian Nairo Quintana, who finished together after the final ascent to Pra Loup, a 6.2-km climb at an average gradient of 6.5 percent.
Froome summed up the stage by saying: "It was a crazy day."
Froome leads Quintana, who attacked him several times in the climbs, by three minutes and 10 seconds and his Movistar team mate Alejandro Valverde of Spain by 4:09.
Contador is now fifth overall 6:40 off the pace, six seconds behind Froome's compatriot and team mate Geraint Thomas.
In 1975, Frenchman Bernard Thevenet snatched the yellow jersey from the great Eddy Merckx in a stage finishing in Pra Loup, but Froome was not to be overthrown on Wednesday.
The Briton showed fine descending skills and his usual power in the climbs to stay in control on another searing hot day on the Tour.
Peter Sagan was again in the day's breakaway as part of a group of 28 that also featured France's Thibaut Pinot and American Andrew Talansky.
In a nervous start to the stage, Van Garderen dropped out of the main pack early on suffering from a headache.
Shortly after making contact with the peloton again, he stepped off his bike and abandoned the race about 73-km from the finish.
World champion Michal Kwiatkovski of Poland also abandoned the Tour later in the stage.
Contador jumped away from the peloton with team mate Michael Rogers in the ascent to the Col de la Colle St Michel but was quickly reined in and the Team Sky-led pack let the breakaway build a nine-minute lead.
Geschke powered away from that leading group before the tough ascent to the Col d'Allos -- at 2,250 meters the highest point of this year's Tour.
Lagging two minutes behind, Pinot launched the chase and at the top of the Col d'Allos had halved the deficit.
But in the descent the Frenchman skidded off and crashed. He quickly remounted but had cut his legs and only managed fourth behind Talansky and Colombian Rigoberto Uran respectively.
Reporting by Julien Pretot; Editing by Ken Ferris