The seven-time Tour de France champion competed in mainland France for the first time this year on Tuesday and was called in for a random doping test after the first stage of the four-day Circuit de la Sarthe.

The 38-year-old Texan rode for Team RadioShack and placed 24th, trailing in the main pack just a split second behind winner Luis Leon Sanchez of Spain.

Sanchez rode for Caisse d'Epargne and made his move near the end of the 114-mile ride from Sable-sur-Sarthe to Varades. He finished in 4 hours, 9 minutes, 5 seconds. Marko Kump of Slovenia trailed and Anthony Ravard of France was third.

Sanchez has a 4-second lead over Kump, while Armstrong trails by 10 seconds.

Shortly after the race and with fans trailing behind, Armstrong wheeled over to the doping-control trailer and roughly parked his bike and went inside. He happened to be one of two riders chosen at random among the 89 riders for testing.

The tests results won't be known for days, but it was a reminder of the barrage of doping tests that Armstrong has faced in France over the years. Armstrong has called himself the world's most-tested athlete, and last year faced dozens of doping tests-all negative-in his return from retirement.

On the way out, he did not speak to reporters or spectators. Armstrong did comment on his Twitter page, but not about the testing.

"St(age) 1 of Sarthe done. Fast stage. Took 120 (kilometers) before breakaway finally went," Armstrong wrote. "Nuts. Good racing tho."

Armstrong also wrote that six of his eight teammates who rode Sunday in the Tour of Flanders were "down and out (with) a stomach bug."

Armstrong later added he was "sicker than a dog now. This sucks."

RadioShack rider Sam Bewley of New Zealand dropped out of the race, with team officials saying he felt ill.

Armstrong's team announced Tuesday he won't compete as planned in the Amstel Gold race in the Netherlands on April 18. He'll return to the United States after the Sarthe race ends Friday.

"His desire was not to win the Amstel Gold race, it's to win the Tour de France-that's what it's all about," team spokesman Philippe Maertens said.

He also appears unlikely to return to Europe this month for two Belgian races, the Fleche Wallonne and the Liege-Bastogne-Liege.

Armstrong wants to spend more time with his family and feels he is fit enough to touch up his form at home before the Tour de France in July, Maertens said. Armstrong wants to join his son, Luke, for the Pinewood Derby car race.

"It's a father-son race ... he wants to be there," Maertens said.

Armstrong will race in the Tour of California next month, then decide whether he will compete in either the Dauphine Libere or the Tour of Switzerland in June, Maertens said.

"Lance needs more stage races than one-day races," he said.

There are two half-stages on Wednesday: a 60-mile ride from Varades to Angers, then a 4.2-mile time trial.