The Australian cyclist Cadel Evans dropped from second overall to third after the mountainous 12th stage of the Tour de France won by Olympic champion Samuel Sanchez of Euskaltel.
Frenchman Thomas Voeckler, of Europcar, upset the formbook to retain the race leader's yellow jersey after the first of three consecutive days in the Pyrenees.
On the first high mountain stage of the race defending champion Alberto Contador lost over 10secs to his key rivals when he dropped off the pace late on the 13.3 kilometre climb to the Pyreneean ski station of Luz Ardiden.
The Spaniard Sanchez came over the finish line ahead of Belgian Jelle Vanendert of Omega-Pharma after attacking his fellow breakaway companion in the final 500 metres.
Overall contender Frank Schleck, who had escaped from the yellow jersey's chase group earlier, finished third, just ahead of a group which contained fellow rivals Evans, Ivan Basso and his younger brother Andy Schleck.
In the overall standings Voeckler now leads Frank Schleck by 1min 49sec, with Evans third at 2:06 and Andy Schleck fourth at 2:17.
Contador, who lost over a minute to his rivals in a crash on the first stage, is now seventh overall at 4:00 behind.
Sanchez claimed his maiden Tour de France stage victory on the 211km ride from Cugnaux.