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, putting him within seconds of the yellow jersey and quashing Alberto Contador’s hopes of a fourth title.

France’s Thomas Voeckler, in a show of grit of his own, narrowly kept the lead by muscling up a punishing final climb to limit the damage at the end of the 125-mile trek from Pinerolo, Italy, to the 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.

“Victory is impossible now,” he 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.”

Schleck began the day in fourth place and is now 15 seconds behind Voeckler. He attacked on the second of three grueling climbs and held on all the way to the fabled Galibier pass to the highest-altitude finish in the race’s 108-year history.

“I told the team (Wednesday) that I had this in mind. I wasn’t going to be fourth in Paris,” Schleck said. “I said I’d risk it all. … It’s my character: I’m not afraid to lose.”

Standing next to Schleck, Voeckler — who has repeatedly insisted that he can’t win when the race finishes Sunday in Paris — said: “You’ll get it.”

Frank Schleck was second Thursday, trailing his brother by 2 minutes, 7 seconds. Cadel Evans of Australia was third. Voeckler was fifth, 2:21 behind. Frank Schleck is third overall, 1:08 back. Evans is fourth, 1:12 off the pace.

Contador was the day’s biggest loser, trailing in 15th place — 3:50 behind. Overall, he trails the French leader by 4:44 in seventh place.

“Please, let me breathe,” an exhausted Voeckler said 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.

Today, 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.

The pack scaled more than 37 miles of total climbs, about one-third of which had a gradient of more than 9 percent.

Andy Schleck took his chance on Col d’Izoard. After riding behind Leopard Trek teammate Stuart O’Grady, the Luxembourg rider sped from 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 in Paris on Sunday.

The stage showed how teamwork and strategy can be essential. 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 34 miles 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. With less than 20 miles left, nearing the foot of the final climb, Schleck and four other breakaway riders caught Maxim Iglinsky, who had ridden solo at the front for much of the stage.

With more than six miles to go, Schleck was continuing to gain time and was ahead by nearly 4 minutes. Evans then attacked the pack, but his speed wasn’t enough to erase the gap of more than a minute.

Today’s Stage 19 features two more “beyond category” climbs.