AS was widely expected, Britain's Chris Froome exploded the Tour de France peloton yesterday with an irresistible stage win, that took him into the race lead, at Ax 3 Domaines ski station in the Pyrenees.

Froome, who started this year's Tour as the pre-race favourite, attacked a select band of remaining rivals, including former Tour champion Alberto Contador, in the closing kilometres of the final climb, before soloing clear to a memorable victory.

"This is only the first week of the Tour," Froome said. "We've still got two weeks to go and there's definitely going to be some hard racing to come. We've got the yellow jersey and we're definitely going to have to defend it."

It was the third fastest ascent of the Pyrenean climb – the second fastest was 15 seconds quicker set by Lance Armstrong in 2001 – and Nairobi-born Froome should now go on to win this Tour, even if we are still two weeks from Paris.

It was billed as the opening round of a long sparring match but Froome went for the knock-out blow on the first true mountain stage of the 100th Tour de France.

The Team Sky rider became the sixth Briton to wear the yellow jersey after leaving his rivals for dead, opening up huge advantages in the general classification (GC) battle. As he kicked out of the saddle a little over five kilometres from the finish, his rivals could only watch on in despair as he disappeared up the road.

"It's a dream come true," said Froome, who made it look easy even if he insisted he was straining every sinew around the final corners. "I definitely wasn't holding anything back then. This is the Tour de France. Every second counts. I wasn't trying to save myself there."

There was an air of inevitability about the attack, as Froome had already shown what Team Sky principal Sir Dave Brailsford described as "very fruity" form during the opening skirmishes on Corsica.

"I made the call when I saw the other guys were really struggling," Froome said. "I thought this was the right moment to push on and get a bit of time."

Sky could barely have scripted the day better as they kept a sure pace at the front of the peloton over the imposing Col de Pailheres, at 2001 metres the highest peak of this mountainous route, and delivered Froome to the front on the road to Ax 3 Domaines.

Richie Porte was Froome's final lead-out man, but rather than drop back he delivered another blow to the already reeling Alejandro Valverde and Alberto Contador by pushing on to finish second.

Earlier, Geraint Thomas had done another huge turn at the front on his cracked pelvis, while Peter Kennaugh earned plaudits by leading the Sky train over the final leg of the Pailheres, down the long descent and onto the final climb before peeling off seven kilometres from the finish.

By then, they had chased down a long breakaway from Nairo Quintana – the last man standing after a string of attacks on the punishing climbs in searing heat.

"We didn't miss a beat," Porte said. "We just reeled them in nice and slowly. Pete for me was the ride of the day - he was just phenomenal."

Tour debutant Kennaugh, who won Olympic gold in the team pursuit in London, had been one of the last to get his place in the Team Sky squad but demonstrated exactly why he had earned the trust of Brailsford today.

"I was a bit nervous about whether I was going to perform and whether I could live up to the job that I had to do," he said. "Today, I proved why I was selected."

Froome finished 51 seconds ahead of Australian Porte while Valverde was third, now 1min 25 secs down. And Contador's eighth place means the two-time winner is already facing a deficit of 1min 51 secs in the GC battle.

Other GC contenders fared worse. Joaquim Rodriguez is 2mins 31 secs off the pace while Cadel Evans admitted his hopes were effectively over as he has a deficit of 4mins 36 secs.

But Froome remained cautious. "We're going to have to see how the race goes," he said.

It was on women's finals day at Wimbledon last year that Froome won stage seven of the Tour in La Planche des Belles Filles to put his team-mate Sir Bradley Wiggins in yellow – a jersey he wore all the way to Paris.

That is the formula Sky will look to repeat now with a squad fully united around Froome, who is growing in stature as the unquestioned leader with Wiggins absent through injury.

"It's so easy to commit to Froomie, the way he handles everyone," Kennaugh said.

"He has respect for every rider no matter what the job is. Every time you give 100 per cent for him because you know you'll get it back."