MONACO — Lance Armstrong put in a solid performance in his comeback at the Tour de France yesterday, finishing the first stage ahead of 170 riders many years younger and a respectable 10th behind winner Fabian Cancellara.

Armstrong's Astana team was dominant in the time trial through the hills and hairpin turns of Monaco, led by the cyclist who would be his heir as Tour titan — Alberto Contador of Spain.

The Texan, who has a record seven Tour victories, is making his return to cycling's showcase event after ending a 3 1/2-year retirement this winter. The 37-year-old Armstrong, one of the oldest riders in the pack, had a chance to test out his legs and state of mind.

"I was nervous, I was excited, and trying to focus on doing the right race specifically in terms of starting easy and finishing good," he said. "When I finished, I was tired — yeah, it was a hard race."

Cancellara took the yellow jersey by finishing the 9.6-mile time trial in 19 minutes, 32 seconds — 18 seconds ahead of Contador, the 2007 Tour winner.

"I didn't expect to win or to take the jersey. I didn't expect a super, super performance," Armstrong said. "It's been a long time since I've had that emotion of being on the start ramp at the Tour."

The race against the clock, in which riders set off one by one, offered an early shakeout about the potential contenders to win the three-week cycling showcase.

"Fabian is a great champion ... (but) my form is very good," the 26-year-old Spaniard said. "I must try to keep up this level. I think I have started well."

Contador was forced to sit out last year because of doping problems at Astana before he joined. He is a far better climber than Cancellara, and the Pyrenees loom in Stage 7.

Contador led four Astana riders into the top 10. Andreas Kloeden of Germany was fourth, American Levi Leipheimer was sixth and rival Armstrong was 40 seconds back in 10th.

Carlos Sastre, the reigning Tour champion, was 1:06 behind Cancellara.