LE MONETIER-LES-BAINS, France - Andy Schleck led a daring attack in the Alps to win the 18th stage of the Tour de France on Thursday, a display of panache that puts him within seconds of the yellow jersey and quashed Alberto Contador's hopes of a fourth title.

France's Thomas Voeckler, in a show of grit of his own, narrowly kept the coveted leader's shirt by muscling up a punishing final climb to limit the damage at the end of the 205-kilometer (125-mile) trek from Pinerolo, Italy, to Galibier Serre-Chevalier ski station in France.

Contador started the stage trailing Voeckler by several minutes after a rough start to the three-week race and finished it with a dismal final climb, leading him to declare that his chances in cycling's showcase race were over.

"Victory is impossible now," Contador said. "I had a bad day. My legs didn't respond and I just hit a wall. It was a very difficult day right from the start."

Video   Andy Schleck: "No guts, no glory" July 21, 2011: Andy Schleck, who gained 2 minutes, 21 seconds, credits his team for his amazing Stage 18 ride.

Schleck, a 26-year-old rider from Luxembourg, attacked his top rivals on the second of three grueling climbs and held on all the way up to the highest-altitude finish in the race's 108-year history, on the fabled Galibier pass.

"I told the team yesterday that I had this in mind. I wasn't going to be fourth in Paris," Schleck said of his place in the standings as the stage began. "I said I'd risk it all and it worked well."

"It's my character: I'm not afraid to lose," he said. "Tomorrow is another day, and I hope to have the yellow jersey."

Standing next to Schleck, Voeckler - who has repeatedly insisted that he can't win when the race finishes Sunday in Paris - quipped: "You'll get it."

Frank Schleck was second on Thursday behind his younger brother, trailing by 2 minutes, 7 seconds, and two-time Tour runner-up Cadel Evans of Australia was third.

Video   Schleck makes his move July 21, 2011: Leopard-Trek's Andy Schleck surprises the contenders and makes a charge 60 KM from the finish.

Voeckler was 2:21 behind, the French cyclist keeping his overall lead by a mere 15 seconds from Andy Schleck. The elder Schleck is third overall, 1:08 back. Evans is fourth, 1:12 off the pace.

"Please let me breathe," an exhausted Voeckler told journalists at the finish, mustering the strength to raise a fist in joy once he saw he'd kept the yellow jersey. "At 2,650 meters, the oxygen is thin."

"I limited the damage," he added. "I went all out."

Schleck, the Leopard Trek team leader, came in knowing that he would need to gain time on rivals ahead of Saturday's time trial - a discipline that's not his specialty.

On Friday, the pack faces the last of three days in the Alps. It again features an uphill finish at the renowned and dreaded Alpe d'Huez.

Ahead of the stage, Contador tweeted in Spanish about "What leg pain!" awaiting on three climbs so tough that they defy cycling's rating climbs: the Col d'Agnel, the Col d'Izoard and the Col du Galibier.

Video   Frank Schleck: "Everything went perfect" July 21, 2011: Frank Schleck, currently third just behind brother Andy, says Stage 18 went just as planned.

By the end, the Spaniard was the day's biggest loser, finishing in 15th place - 3:50 behind. Contador now trails Voeckler by 4:44, in seventh place overall.

The pack scaled more than 60 kilometers (37 miles) of total climbs, about one-third of which had a gradient of more than 9 percent. Tour director Christian Prudhomme called the 23.7-kilometer (14.7-mile) Col d'Agnel - at 2,744 meters (9,000 feet) - the hardest climb in this year's race.

Agnel, the day's first big climb, wasn't the site of the showdown. At one point there, Contador drifted back to the race doctor.

"The start of the stage didn't get off well, I had to drop back to the medic car for an anti-inflammatory," he said.

Andy Schleck took his chance on Col d'Izoard. After riding behind Leopard Trek teammate Stuart O'Grady, the Luxembourg rider sped out of the main pack about midway up, with 13 breakaway riders ahead.

Contador moved up to the front of the pack, but didn't chase. Neither did Voeckler or Evans, possibly a tactical error that could cost them victory Sunday on the Champs-Elysees.

Video   Voeckler: "It's like a miracle" July 21, 2011: Tour leader Thomas Voeckler kept his overall lead with a stirring late finish.

The stage showed the importance of teamwork and strategy. Leopard Trek sent out two riders in the breakaway so they'd be available to escort Schleck in case he could shake his rivals.

He did. With 56.6 kilometers left in the stage, Schleck jumped out to a lead of more than a minute against the contenders and caught his teammate Joost Posthuma, one of the breakaway riders who welcomed Schleck into his wake to go up Izoard.

Schleck crossed the top alone, still behind the rest of the breakaway but about 2 1/2 minutes ahead of Evans, Voeckler and Contador. On the downhill - not one of Schleck's strengths - Schleck caught up with Belgian teammate Maxime Monfort, who slowed down to escort him.

With 30 kilometers left, nearing the foot of the final climb, Schleck and four other breakaway riders caught Maxim Iglinsky of Kazakhstan, who had ridden solo at the front for much of the stage.

Twenty kilometers later, Schleck was continuing to gain time, and was ahead by nearly 4 1/2 minutes. Evans - seeing his title hopes face - mustered his response by attacking the pack, but he wasn't able to erase the gap.

Video   Evans on the day: "Bizarre" July 21, 2011: Cadel Evans dropped from second to fourth in Stage 18 as team strategies came into play.

With 7.8 kilometers left, Schleck was alone with Iglinsky close on his rear wheel but he moved away from the Kazakh to ride alone, gritting his teeth and spitting water slurped from his bottle.

"The riders ahead of him worked well, and he possibly already had some kind of agreement in place," Contador said of Andy Schleck. "It was a smart tactic and you have to congratulate him on that."

Friday's Stage 19 features two more "beyond category" climbs. One heads up the other side of the Galibier, which wasn't covered Thursday, and the Alpe d'Huez finish after a 109.5-kilometer (68-mile) trek from Modane.

A key question for the final race days is whether Andy Schleck may have depleted himself too much - and whether his fatigue could give an opening to Evans, who many think could be his biggest threat for overall victory now.

"By the end, I could do any more. I crossed the line and I had gone all out for every second," said Schleck, his neck bundled in a post-race towel to protect him from mountaintop cold. "I haven't hurt like this in a long time."

Video   Stage 19: Alpe-d’Huez June 20, 2011: The famous and dreaded mountaintop finish awaits Andy Schleck, Cadel Evans and the rest of the Tour on Friday.

He said Contador, despite the Spaniard's own insistence, still can't be ruled out. "He's not out of the race, but we see clearly that he's beatable," he said.

Evans said he "couldn't control" such an early attack like the one by Schleck, and was a bit baffled by the pace of the Luxembourg climbing star and the rest of the lead bunch.

"They really rode fast at the front. I don't quite understand how they made so much time," the Australian said.

The pain was widely shared on the climbs, putting Schleck's margin of victory into sharp relief.

More than half of all riders finished so far back from Schleck that they would normally have been disqualified. But Tour organizers invoked a race rule that allowed them to keep competing - with a penalty.

The penalty lopped off 20 points from the stragglers in the competition for the green jersey for best sprinter. Britain's Mark Cavendish saw his tally fall to 300 points - just 15 ahead of Jose Joaquin Rojas of Spain.

Evans said he's looking ahead to the time trial, which is more a specialty for him than the Schleck brothers.

"It was always going to be crucial, but as long as we are within one or two minute of each other - such a hard time trial - there can be big gaps if you arrive there a little less fatigued than those around you," Evans said.