Contador flexes his muscle

The Spaniard surged ruthlessly with six kilometres left in the 207.5-km 15th stage to the Swiss ski resort of Verbier to collect the stage laurels and his first yellow jersey since his 2007 victory in Paris.

"I'm very pleased with this result. It was not a very long climb but we tackled it very rapidly and I was able to move as I wanted," the 26-year-old told reporters. "I saw there was a chance with five kilometres to go and I did what was required to make a difference," he added. Second place in the stage went to Luxembourg champion Andy Schleck, the only rider almost on par with Contador in the climbs, who crossed the line 43 seconds behind him.

Italy's Vincenzo Nibali was third ahead of the other leading Tour contenders but all eyes were on Armstrong in the final climb to Verbier.

The American discovered his 37-year-old legs were probably not fit enough for him to challenge Astana team mate Contador any longer.

He finished 1:35 off the pace, which was enough to put him second overall, 1:37 behind the rider he will assist from now on.

Armstrong, who returned to competition in January after 3-1/2 years retirement to try and win an eighth Tour, conceded defeat. "Sure Alberto is the best rider. Sure he is the best climber. You know when everybody is to the limit and you can accelerate again, that's how you win the Tour. I have been there."

"As far as I'm concerned, I'm happy to be his domestique. I'm proud of him," he said.
Contador acknowledged he was now the undisputed leader of both his team and the Tour. "The situation is now very favourable to me. Of course the team is behind me. They worked great all week and they will continue to do so next week."

Contador will keep the yellow jersey until Tuesday at least as the peloton enjoy a one-day break in Martigny.