Lance Armstrong rides Tuesday in a cloud of dust on a cobblestone section during the third stage of the Tour de France that covered 213 kilometers (132.4 miles) from Wanze, Belgium, to Arenberg, France.

ARENBERG, France — Lance Armstrong has good reason to be frustrated.

Although the 38-year-old American posted his best time trial result in five years before handling treacherous cobblestones sections with authority on Tuesday, Armstrong is already in trouble following the first three stages of the Tour de France.

The seven-time champion dropped from fifth to 18th in the overall standings and now trails the main contenders after a flat tire cost him significant time during the third stage of the race.

Armstrong, who got off to a strong start in the Tour with a fourth-place finish in last week's prologue, had another strong display during Tuesday's daunting third stage from Wanze, Belgium, to Arenberg Porte du Hainaut, France, which featured seven sectors of cobbles.

Armstrong looked comfortable in the dust, handling his bike well on tiny and dented roads. At one point, Armstrong held a small lead over defending champion Alberto Contador of Spain, who ended up in 13th place, 1 minute, 13 seconds behind stage winner Thor Hushovd of Norway.

Armstrong placed 32nd, 2:08 behind.

"Sometimes you're the hammer, sometimes you're the nail," Armstrong told reporters at his team bus. "Today I was the nail. I have 20 days now to be the hammer."

Armstrong, who began the stage ahead of his rivals, lost about 45 seconds when he punctured in the penultimate sector of cobblestones.

"We were all just pulling through, really trying to gain as much time on Lance and the guys who were at the back," said Bradley Wiggins of Britain, who has a 41-second edge on Armstrong.

In the overall standings, Fabian Cancellara of Switzerland leads Geraint Thomas by 23 seconds. Two-time Tour runner-up Cadel Evans is third, 39 seconds back, and Contador is ninth, 1:40 behind. Andy Schleck is sixth, 1:19 back.

Armstrong, who is 2:30 behind, admitted that his hopes of winning an eighth Tour de France title suffered a blow.

"Our chances took a knock today," Armstrong said. "I'm not going home, we'll stay in the race and we'll keep trying."