Seven-times Tour de France winner Lance Armstrong finished 10th in the prologue at the Tour of California on Saturday in the first North America race of his comeback.

Armstrong, who made his comeback debut three weeks ago in the Tour Down Under in Australia, finished in four minutes, 37.17 seconds, 4.2 seconds behind prologue winner Fabian Cancellara of Switzerland.

"It's a new sensation because I haven't trained for efforts like that," Armstrong said after completing the 3.9-kilometre course around California's state Capitol.

"We changed the time-trial position a little bit, so it's the first time I got to go as hard as I could with a new position. All in all, I wanted to be top-10, top-15, so I have to be pretty happy."

Cancellara, a former two-times time trial world titlist, won in 4:32.9 seconds, with American Levi Leipheimer, twice defending race champion, second in 4:34.11. Third was American David Zabriskie in 4:35.55.

Armstrong, the 130th starter in a field of 136, attracted massive attention. He rode steadily in a tight tucked position and received the largest cheers on the overcast start of nine-day race's fourth edition.

"The crowd was amazing, they were like it was Australia," Armstrong said.

"People are excited, but I don't think they're as excited as I am. I'm glad to be here and appreciate the support."

Cancellara, who won the 2007 Tour de France prologue, averaged 50.294 kph.

"It was big on the agenda for us to get this win for the team," said Cancellara. "Now the pressure is gone and we can see and enjoy the (leader's) jersey."

Floyd Landis, the dethroned 2006 Tour de France champion competing for the first time following a two-year doping suspension, finished 90th in 4:53.26, more than 20 seconds behind the winner. Landis crashed during a training ride on Thursday.

Carlos Sastre of Spain, the reigning Tour de France titlist who is competing in the United States for the first time, finished 114th in 4:58.59.

The nine-day event continues on Sunday with a 173.2-kilometre stage one road race from Davis to Santa Rosa, California.