SAINT-ETIENNE, France -- No "crazy" attacks, conserve energy, and hope for the best in the time trial: Tour de France leader Carlos Sastre is tipping his strategy as the race creeps toward its finish in Paris on Sunday.

The Spanish veteran didn't see the chance he was looking for to expand his lead against his top rivals in Thursday's 18th stage out of the Alps, which Germany's Marcus Burghardt won by heading a two-man breakaway.

With a flat ride on tap for today, the final showdown in cycling's premiere event comes in Saturday's Stage 20 -- a 32.9-mile race from Cerilly to Saint-Amand-Montrond.

Sastre insists he doesn't want to think about that stage just yet, but time trial aces Cadel Evans of Australia and Russia's Denis Menchov -- who are among those nipping at his heels -- are clearly on his mind.

"At the Tour, you have to be wise and place your attacks well," said the 33-year-old Team CSC leader. "It's true that today was hard, but not enough to put Menchov or Evans in difficulty.

"There was no reason to lead a crazy attack," said Sastre, who has finished in the top 10 at the Tour five times. "Now, it's better to rest well for Saturday and keep my energy for the time trial."

Sastre leads his CSC teammate Frank Schleck of Luxembourg by 1 minute, 24 seconds, and Austria's Bernhard Kohl is third, 1:33 behind. Evans is fourth, 1:34 back, and Menchov trails by 2:39 in fifth.

Of those, Evans, the 31-year-old Silence Lotto leader and Tour runner-up last year, appears to be the best-placed to take the yellow jersey off Sastre in time for Sunday's finale of the three-week race on the Champs-Elys¿es.

The title hopefuls were content to let Burghardt, a 25-year-old Team Columbia rider, and Carlos Barredo of Spain speed ahead during Thursday's 122.1-mile ride from Bourg-d'Oisans to Saint-Etienne.

Barredo came into the stage more than 2 hours behind Sastre, and Burghardt was more than three hours back. The two riders often attacked each other in the last 6 miles, and at times chatted.

The German raised his fists in the air and clapped after he won a sprint against Barredo, who banged his handlebars in frustration. They finished in 4 hours, 30 minutes, 21 seconds for the ride through minor mountains.

Sastre and his main rivals in the title hunt finished 6:50 behind.