Lance Armstrong (search) retained his overall lead in the Tour de France's flat, fast stage 13 on Friday, won by Robbie McEwen in a sprint.

The win was McEwen's third of this year's Tour. Armstrong and his main rivals finished together in the stage across southern France before the race heads into the Pyrenees (search) on Saturday.

Armstrong's lead over second-place Mickael Rasmussen of Denmark stayed at 38 seconds, with French rider Christophe Moreau still third, 2:34 behind the six-time champion.

Italy's Ivan Basso (search) remains 2:40 back, fourth overall. Jan Ullrich of Germany is 4:02 behind, but rose to eighth in the standings after Spain's Alejandro Valverde retired with an injury. Valverde, winner of the first Alpine stage, had been fifth overall.

"Everybody is waiting" for the Pyrenees, said Armstrong, explaining why he and his rivals did not do battle over Friday's 107.8-mile trek from Miramas to Montpellier.

Ullrich was 25th, Armstrong 33rd, Rasmussen was 57th, and Basso was 72nd. They and McEwen all finished with the same time of 3 hours, 43 minutes, 14 seconds.

McEwen attributed his victory to his Davitamon-Lotto team, which helped reel in a group of riders that had escaped, setting the Australian sprinter up for his dash to the line.

"It's not a victory for McEwen, it's a victory for Davitamon-Lotto," he said. "Unbelievable."

The first of the three Pyrenean stages has five progressively harder climbs before finishing with a steep ascent to Ax-3 Domaines.

Armstrong, looking gaunt and exhausted, placed fourth the last time the Tour visited the ski station in 2003 — the shakiest of his record six wins. Ullrich powered past Armstrong on the climb, cutting the American's overall lead to just 15 seconds. Spain's Carlos Sastre won the stage that day.

Armstrong has been stronger so far this year.

The Ax-3 Domaines climb rates a 1 on the rising scale of difficulty that starts at 4.

Before that final ascent comes the 9.4-mile climb over the Port de Pailheres. It peaks at 6,565 feet and is so hard that it is classified as "hors categorie" — or unrated.

The ascents combined form a "one-two punch," said Armstrong.

"Pailheres is a very tough climb," he added. "Very long, very steep and incredibly narrow at the top."

Saturday's 137-mile stage from Agde on the Mediterranean coast is followed Sunday by perhaps the hardest stage this year.

It has a succession of five climbs, one rated 2, the others 1, before an "hors categorie" final ascent to Saint-Lary Soulan.

Monday is a rest day before the last high mountain stage. Should the Pyrenees not prove decisive, the outcome of the three-week race will likely be decided in a time trial the day before the Tour ends July 24. Armstrong will retire then — he hopes with a seventh consecutive win.

Hot weather is forecast to continue Saturday. Dehydration weakened Armstrong during the 2003 Tour. Sipping water a press conference, he said he is taking care to drink this year.

"Everybody's performance suffers in the heat," Armstrong said. "But some riders, of course, handle it better than others."