Lance Armstrong began his chase for a seventh consecutive Tour de France title in style yesterday by taking second place in the opening time trial.

The American, starting his favourite race for the last time, overtook main rival Jan Ullrich of Germany, who had set off a minute before him, to clock the second fastest time in the day's ride over 19kms from Fromentine to Noirmoutier.

American David Zabriskie was surprisingly two seconds faster than Armstrong and claimed the race leader's yellow jersey.

Alexander Vinokourov, regarded as one of Armstrong's main rivals for final victory on July 24 in Paris, was third fastest, 53 seconds slower than Zabriskie.

On Friday, Armstrong underwent a surprise dope test at his hotel, a control which raised questions as the American was the only rider to be tested.

A stony-faced Armstrong told journalists he had been random tested six times out of competition this season and added he was under the impression the test had been monitored by the French sports ministry.