Defending Tour de France champion Cadel Evans launched a long-range attack in an effort to eat into his deficit to Bradley Wiggins on stage 11 today.
The Australian accelerated out of the Team Sky-led peloton with 81 kilometres of the 148km route from Albertville to La Toussuire remaining.
Evans, who began the day one minute 53 seconds behind Wiggins, had support from BMC Racing team-mate TJ van Garderen on the day's second hors categorie (beyond category) climb, the Col de la Croix de Fer, the summit of which came 55km from the finish.
Michael Rogers, Richie Porte and Chris Froome, who began the day third overall, accompanied Wiggins at the front of the peloton and the Team Sky riders appeared unflustered by Evans' move.
The Australian's gain was marginal and Van Garderen had to slow his pace so his team leader could stay with him.
The high tempo of Rogers and Team Sky saw Evans reeled in quickly as the immediate threat was extinguished.
But it was an indication of what Wiggins and Team Sky were set to expect on the final climb to La Toussuire.
Fredrik Kessiakoff (Astana) and Pierre Rolland (Europcar) led a group of seven riders over the summit and began the descent, which was immediately followed by the day's third categorised climb, the category two Col du Mollard.
Alongside them were Chris Horner (RadioShack-Nissan), Irishman Dan Martin (Garmin-Sharp), Laurens Ten Dam (Rabobank), Robert Kiserlovski (Astana) and Vasili Kiryienka (Movistar).
The yellow jersey group were two minutes behind, with Evans behind Team Sky's four-man climbing squad.
Earlier, Team Sky and Bradley Wiggins played a watchful role at the start of the 148-kilometre 11th stage of the Tour de France from Albertville to La Toussuire on Thursday.
Wiggins predicted the route, featuring two hors categorie (beyond category) climbs would be the toughest day of the Tour, but he was content to allow a large early break to form on the day's first brutal ascent, the 25.3km Col de la Madeleine.
Irishman Dan Martin (Garmin-Sharp) was part of the early break, which featured 26 riders, the best-placed being Michele Scarponi (Lampre-ISD), who began the day seven minutes 14 seconds behind.
Two members of Vincenzo Nibali's Liquigas-Cannondale team were also in the break as the Italian, who started the day in fourth, 2mins 23secs behind, sought support in his bid to reduce the deficit.
Team Sky led the peloton, with Christian Knees handing over to Edvald Boasson Hagen midway up the Col de la Madeleine as the peloton remained within two minutes of the leaders.
The stage was set to finish at La Toussuire, which is infamous for being the stage which cracked Floyd Landis in 2006.
The American recovered miraculously to win the following day's stage and was later stripped of the 2006 Tour title following a positive test for testosterone.
Peter Velits (Omega Pharma-QuickStep) led Fredrik Kessiakoff (Astana) going over the summit, with Wiggins' group three minutes behind.
Nibali and Peter Sagan (Liquigas-Cannondale) moved ahead before cresting the summit ahead of the long descent, but there was a long valley to negotiate before the second hors categorie climb, the Col de la Croix de Fer, the summit of which came 55km from the finish.
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