ARENBERG, France -- Lance Armstrong's hopes for victory in his final Tour de France hit a setback Tuesday when a burst tire cost him time during a jarring stage over cobblestones that was won by Norway's Thor Hushovd.
Fabian Cancellara of Switzerland finished the third stage in a five-man group behind Hushovd, but he regained the yellow jersey he ceded a day earlier to Sylvain Chavanel of France. Hushovd was ahead of Geraint Thomas of Britain and world champion Cadel Evans of Australia in a sprint finish among the leading group of riders.
The 132-mile ride from Belgium to France was the most dreaded stage of week one -- with seven sections of bone-jarring cobblestones that threatened injury, bike damage or lost time for contenders.
"Bad luck," Armstrong said, referring to his mishap in the fifth patch.
Some had worse luck: Frank Schleck of Luxembourg, who won the Tour of Switzerland last month, crashed on the fourth section and was out of the race and taken to hospital.
Armstrong noted there's still a lot of racing left in the three-week race, which now heads toward the Alps and later the Pyrenees before the Paris finish on July 25.
"It's the nature of the sport," he said. "Sometimes you're the hammer, sometimes you're the nail. Today I was the nail. I have 20 days now to be the hammer."
Armstrong had predicted "carnage" during the stage, one that many riders thought could damage plenty of title hopes. The seven-time champion and Schleck were the day's most prominent losers.
Defending champion Alberto Contador, whose abilities on cobblestones had been in doubt, and last year's runner-up Andy Schleck, Frank's younger brother, were among contenders who gained time on Armstrong.
Andy Schleck was fifth, in the same time as Hushovd: 4 hours, 49 minutes, 38 seconds. Spain's Contador came in 13th, 63 seconds back. Armstrong was 32nd, 2:08 back.
In the overall standings, Cancellara leads second-place Thomas by 23 seconds and two-time Tour runner-up Evans by 39. Contador is ninth, 1:40 back, and Armstrong tumbled to 18th, 2:30 back. He had been fifth overall.
Cancellara, a teammate of the Schlecks who won the opening-day prologue, expressed "mixed feeling" about the day but was delighted to retrieve the leader's jersey.
"Yesterday I gave it up, today I took it," he said. "We can call it a good day for Saxo Bank despite the loss of Frank, a great friend."
Seven riders broke away early. Getting out front in such a stage doesn't just improve chances for a stage victory, it also can help avoid crashes -- which are more likely in the frenzied pack.
Even before the cobblestone sections, several riders collided near the 70-mile mark after one rider bumped into the curb and fell. France's David Le Lay was forced out the race.
Armstrong's RadioShack team led the pack over the first bumps, with crowds getting up close but respecting a safe enough distance for the riders to get through.
After the first, Simon Gerrans of Team Sky bloodied his right cheek in what appeared to be a solo spill, but he got back on his bike and returned to the race.
At the second patch, dust flew as some riders sought to evade the cobblestones by riding on the dry dirt on the side -- but again, no riders went down. This time, the crowds kept back.
Frank Schleck, in the middle of the Sars-et-Rosieres patch -- the fourth run of cobbles -- hurtled off his bike and onto the side of the road, and did not get up, crouching in pain on the ground.
The pack then splintered. Armstrong had a small lead over Contador after the fifth section, but then he got a flat tire in the sixth and the Spaniard's group rumbled by him until the Texan got a replacement.
"It was bad luck," Armstrong said, acknowledging that the result has dented his hopes for an eighth Tour victory. "They've dropped, no doubt, we've lost significant time."
Chavanel wore the yellow jersey for Tuesday's ride into his home country, but he had to cope with two flat tires, along with a mechanical problem, and lost time on Cancellara.
"It's not bad, I just didn't have the legs," said Chavanel, with his face caked in dust. He won Monday's stage in a breakaway that took a lot out of him. "I had a nice day in yellow, over the cobbles, it's great."
The pack could get a more restful day Wednesday, with a mostly flat 95-mile trip from Cambrai to Reims, the capital of Champagne country.
The cobblestone stage, the first at the Tour since 2004, followed two straight days marred by crashes on slick roads that ensnared Contador, Andy Schleck and Armstrong.
American Christian Vande Velde was one of two riders who crashed out. The Garmin-Transitions team leader broke two ribs in a spill during Monday's ride from Brussels to Spa.