Bradley Wiggins of Britain took another step towards securing his maiden Tour de France crown after a 16th stage won in stylish fashion by Frenchman Thomas Voeckler on Tuesday.
Yellow jersey holder Wiggins repelled a number of attacks by Vincenzo Nibali on the fourth and final climb to come over the finish with his Italian rival and Sky teammate Chris Froome around seven minutes behind a triumphant Voeckler.
Defending champion Cadel Evans of BMC finished nearly 12 minutes behind Voeckler and nearly five minutes behind Wiggins' group after being dropped for good on the Col du Peyresourde.
It means the Australian drops from fourth overall to seventh at 8:06 behind Wiggins and virtually ends his bid to defend his 2011 title.
He has been replaced in fourth by Lotto team leader Jurgen Van den Broeck (5:46), with Spaniard Haimar Zubeldia in fifth at 7:13 and American teammate Tejay Van Garderen in sixth at 7:55.
Evans started trailing on the Col d'Aubisque, came over the summit of the penultimate climb with a 45secs deficit to Wiggins and then fought to get back on before the final climb to the summit of the Peyresourde.
Not long after the road started rising, however, the Australian lost touch with Wiggins' group when a turn of pace by Van den Broeck's teammate Jelle Vanendert split the group and just proved too much.
"Cadel was maybe suffering from the heat and had some stomach problems. It was just a bad day," said Van Garderen, who now has a chance to finish ahead of his team leader in Paris.
"I think now it's more of co-leadership. He's still only one place behind me."
After another impressive day in the mountains by Sky, Wiggins retained his 2min 05sec lead over Froome, with Liquigas rider Nibali still third at 2:23.
Voeckler, meanwhile, grabbed his second stage win of the race and the fourth of his career after leaving breakaway companion Brice Feillu of Saur-Sojasun behind with 22 km remaining and 7km from the summit of the Col du Peyresourde.
Although he was countered by Saxo Bank's Chris Anker Sorensen, the Dane who is famous for his lively grimacing as he pulls himself up the climbs, was never a threat to the Frenchman.
Sorensen eventually came over the finish nearly two minutes behind Voeckler, giving the Europcar rider plenty of time to savour his second victory in Luchon, two years after winning stage 15 in 2010.
It was also the fifth victory of the race for the hosts, following wins for Thibaut Pinot (FDJ), Pierre Rolland (Europcar) and Pierrick Fedrigo (FDJ).
"For me it was like four races today," said Voeckler, who won stage 10 in Bellegarde-sur-Valserine.
"And each one was a climb. I never go and look at stages beforehand but I've been racing these mountains since I was 19 years old.
"I knew this stage off by heart. I was leading each time I went over a mountain pass."
Voeckler's efforts meant he clocked major points at each summit, meaning he took over possession of the King of the Mountains' polka dot jersey from Sweden's Fredrik Kessiakoff.
The 17th stage on Thursday is a 143.5 km ride from Luchon to the summit of Peyragudes and is the last climbing stage of the race.