The first mountain-top finish of the Tour yesterday saw the favourites finally come to the fore, with the American Floyd Landis seizing the yellow jersey by a slender eight seconds and Russia's Denis Menchov taking the stage win.
On the last of five Pyrenean climbs, the 13-kilometre Pla de Beret in Spain, Menchov's Rabobank team-mates laid down a ferocious pace on the lower slopes that shredded a leading group of 19 riders.
An attack by Menchov saw the favourite, the German Andreas Klöden, slide backwards, and then another by the American Levi Leipheimer cut the lead group to three, himself, Menchov and Landis.
A sea of Basque cycling fans, clad in the orange colours of their Euskaltel-Euskadi team made it difficult for Landis to progress to the final, flatter, two kilometres of the stage.
Nor could the Phonak rider prevent the 2005 Tour of Spain winner Menchov, followed closely by Leipheimer, from cutting ahead on the final corner - an advantage the Russian held all the way to the finish.
"We've shown today that we've the strongest team of the race." Menchov said. "Personally, I think my condition is as good as last year in the Tour of Spain."
It was touch and go whether Landis could take the yellow jersey as he was 4min 45sec back on the overnight leader, the Frenchman Cyril Dessel. But despite producing a ferocious effort, Dessel witnessed the race lead slip through his fingers by just eight seconds.
"I wasn't interested in the stage win, my main priority was gaining as much time as possible on the other favourites." Landis said. "If there's no stage victories between here and Paris and then I win the Tour, I'm not complaining." Due to have an arthritic hip replaced after the Tour, the former mountain biker is acutely aware of of the effect the injury may have on his chances. "For now I'm taking it day by day, and I'm honoured to have the yellow jersey."
If Dessel's narrow defeat was hard for the Frenchman to swallow, other more famous riders suffered a far more humiliating day.
Klöden's loss of 1min 30sec to Landis all but pushes him out of the running, but for American George Hincapie, who lost over 20 minutes, the Pyrenees proved a cruel test too far.
While Landis is in pole position to succeed his former team-mate Lance Armstrong in Paris, his hold on the jersey is far from secure. Three Alpine stages and a long time trial are still to come and his squad, Phonak, are by no means the strongest: on the last climb, Landis had no team support whatsoever.
To cap it all, Landis's closest top rival, Menchov, is just 1:01 behind - the American's chances of a smooth ride to Paris are slim.
Alasdair Fotheringham writes for Cycling Weekly