Tour de France favorite Chris Froome overpowered his main rivals on the first tough mountain climb of the race Saturday and won the eighth stage to take the leader's yellow jersey.
The British rider finished second overall last year behind countryman Bradley Wiggins, but judging by this win it could be difficult to stop him going one better this time.
"I have to thank the team today. They did a great job and got me to the final climb, they are the ones who got me there," Froome said. "It's the first (big) day for the overall classification. There's a long way to go until Paris. There are two weeks left but we want to keep the yellow jersey."
The 28-year-old Froome attacked early into the stage's second big climb up to Ax 3 Domaines — and no one could follow him. His nearest challenger was teammate Richie Porte, who finished 51 seconds behind in second.
"We rode from the front and the team was absolutely perfect today, there was no need to stress," Porte said. "I'm absolutely finished but it was an incredible day."
Two-time Tour champion Alberto Contador lost ground, as did 2010 champion Andy Schleck and 2011 champion Cadel Evans.
Froome took the yellow jersey from South African cyclist Daryl Impey, his former training partner.
Contador was 1:45 behind Froome, Schleck trailed by 3:34 and the 36-year-old Evans was 4:13 back.
In the overall standings, Froome is 51 seconds ahead of Porte and leads third-place Alejandro Valverde by 1:25. Meanwhile, Contador is already 1:51 behind; Schleck is 4:00 back and Evans is 4:36 down.
"I wasn't expecting that much for today," Froome said. "The time gaps were so big, that's quite something. We're in a really good position but we're going to have our work cut out for us, that's for sure."
But given that Froome may attack again in Sunday's second tortuous Pyrenean climbs, he could be well on the way to victory by Monday's rest day.
"I think we're well poised," Froome said. "We're going to have to fight for it but I'm confident in the team we have."
The 195-kilometer (121-mile) trek started from Castres and stayed flat for a long time before ending with the two huge climbs.
The Col de Pailheres came first — a ferociously tough ascent for about nine miles at a gradient of eight percent — and then a shorter but even steeper ride to the finish at the ski resort of Ax 3 Domaines.
Colombian rider Nairo Quintana broke away to launch a brutal attack up Pailheres, and only Frenchman Pierre Roland initially followed him, but Porte led a chase to help Froome steadily gain ground on them.
Schleck, Evans and then Rolland were dropped with about 6 kilometers (4 miles) left to go up to Ax 3 Domaines as Contador desperately tried to stay on Porte's wheel.
Porte had tired Contador to the point that the Spaniard was even struggling to keep up with teammate Roman Kreuziger, so Froome decided it was time to attack.
He climbed with such blistering acceleration it almost looked like he was riding a time trial, blowing past Quintana and then overtaking Porte.
"Everyone knows that Quintana is very strong in the mountains and when he attacked in the first climb it was hard to catch him," Froome said.
On another hot day well into the 30s Celsius (above 90 Fahrenheit), Impey struggled up Pailheres and soon dropped back to join a large group of stragglers.
Roland caught Quintana at the bottom of the final climb up to Ax 3 Domaines, while Froome was about 20 seconds behind with Sky driving from the front of the chasing pack.
That margin was soon eaten up as Froome zoomed to victory.
The 23-year-old Quintana, who finished in the same time as Contador, ended the day in the white jersey for the best young rider.
"It was a tough day, but I dreamt of something like this," Quintana said through a translator. "I hoped I could win it, but the others were really strong. I really thought I could do it but I had no strength left at the end."