Lance Armstrong reclaimed the Tour de France leader's yellow jersey after stage 10 from Grenoble to Courchevel.
The first of the Tour's mountain stages was won by Alejandro Valverde, who just pipped Armstrong after a gruelling category one climb to the finish.
After looking vulnerable in the first week, Armstrong's Discovery team were at their best in the Alps, setting a relentless pace on the final climb.
Armstrong left main rivals Jan Ullrich and Alexandre Vinokourov far behind.
The six-time Tour winner leads the overall standings by 38 seconds from Dane Mickael Rasmussen with Ullrich now over four minutes adrift.
But Armstrong downplayed his advantage saying: "We're in a good position as compared to some of the main rivals - but there's still a lot of racing to go.
"We have another day in the Alps, a transition stage then two very tough days in the Pyrenees, then the final time trial."
Jens Voigt, who started the day in yellow, also dropped a long way down the standings.
Armstrong took over the lead in Tuesday's stage after the last of his team-mates dropped off the pace 10km from the finish.
By the end, just four riders were left to battle it out - Armstrong, Valverde, King of the Mountains leader Rasmussen and Francisco Mancebo.
Armstrong launched a decisive attack in the final kilometre with only Valverde able to respond and the Spaniard then moved through to cross the line first.
Valverde was delighted with his win but played down his hopes of taking Armstrong's crown.
The Baleares rider is fifth overall but is seen as a future hope while Francisco Mancebo, in seventh, is the team's main contender this year.
He said: "I can't find the words to describe what I'm feeling. Winning here is very important for me.
"But now I want to work for the team. There's no question that Mancebo is our team leader. He's going very strong."
Armstrong, riding his last Tour, admitted he was surprised not to have won the stage.
"I was hoping for the stage win, but I think today we may have seen the future of cycling," he said. "Alejandro's strong, intelligent and he's fast. Very impressive."
Ullrich tried to be optimistic despite falling more than two minutes behind Armstrong.
The T-Mobile rider said: "When the tempo went up it felt like the devil had taken my legs away.
"I also had some problems with my breathing. I don't know if it's because of the crash the other day but the result is there to see for everybody."
"Armstrong and his men were superior but not all Tour days are the same."
An exhausted Vinokourov also attempted to put on a brave face after he fell more than five minutes behind the six-times winner.
He said: "I'm not sure what happened. The first day in the high mountains and it's been a bad day.
"The first climb was tough but we got over that. But the last climb, I just completely lost it. Maybe on Wednesday I'll feel better, for now I've just got to recover."
Stage results (Top 10)
1. Alejandro Valverde (Sp) Illes Balears 4hrs 50mins 35secs
2. Lance Armstrong (US) Discovery same time
3. Mickael Rasmussen (Den) Rabobank +9s
4. Francisco Mancebo (Sp) Illes Balears same time
5. Ivan Basso (It) Team CSC +1:02
6. Levi Leipheimer (US) Gerolsteiner +1:15
7. Eddy Mazzoleni (It) Lampre-Caffita +2:14
8. Cadel Evans (Aus) Davitamon-Lotto same time
9. Andreas Kloden (Ger) T-Mobile same time
10. Andrey Kashechkin (Kaz) Credit Agricole same time
Overall standings (Top 10)
1. Lance Armstrong (US) Discovery 37:11:04"
2. Mickael Rasmussen (Den) Rabobank +38s
3. Ivan Basso (It) Team CSC +2:40
4. Christophe Moreau (Fr) Credit Agricole +2:42
5. Alejandro Valverde (Sp) Illes Balears +3:16
6. Levi Leipheimer (US) Gerolsteiner +3:58
7. Francisco Mancebo (Sp) Illes Balears +4:00
8. Jan Ullrich (Ger) T-Mobile +4:02
9. Andreas Kloden (Ger) T-Mobile +4:16
10. Floyd Landis (US) Phonak same time