Cadel Evans admitted his chances of retaining his Tour de France title had gone after he lost a lot of time to overall leader Bradley Wiggins in the 16th stage on Wednesday.
"I was obviously not at my normal level. It's pretty much the Tour de France over for me," said the Australian, who reportedly felt unwell before the start.
Evans was unable to stay with the other Tour favourites in the penultimate of four climbs on the hard, 197.5-km ride in the Pyrenees and was helped by team mates Amael Moinard and Stephen Cummings.
While he made it back on the descent, he was dropped again in the final Peyresourde pass overlooking Bagneres de Luchon, losing four minutes 47 seconds to Wiggins, second-placed Briton Chris Froome and Italy's Vincenzo Nibali.
Evans now finds himself in seventh position, 8:06 adrift, an unbridgeable gap four days before the finish in the French capital of Paris.
A stunned RadioShack team admitted they will have to battle through the remaining stages of the Tour de France after team leader Frank Schleck quit the race due to a positive test for a banned diuretic.
Schleck, who finished third last year, was informed by the International Cycling Union (UCI) late on Tuesday that he had tested positive for Xipamide.