Italy's Giuseppe Guerini won Friday's 19th stage of the Tour de France, with overall leader Lance Armstrong riding safely behind in the main pack.

The six-time champion maintained his comfortable advantage of 2 minutes 46 seconds over Italy's Ivan Basso and 3:46 on Denmark's Mickael Rasmussen heading into Saturday's final time trial.

That race against the clock should determine the top riders' standings ahead of Sunday's final ride into Paris, where Armstrong is expected to collect his seventh straight Tour title before retiring at the end of the race.

"Big day," Armstrong said. "I'll give it everything I have."

The 34.5-mile time trial in Saint-Etienne offers him a last chance to win an individual stage this year. In each of his previous six Tour victories, he always won at least one stage. But so far this year, his only stage victory has been a collective one in the team time trial with his Discovery Channel squad.

The 33-year-old Texan calculated Friday that he has just "five more hours in my career as a cyclist. I'm not terribly sad about that."

Guerini zoomed away from Sandy Casar of France, Franco Pellizotti of Italy and Spain's Oscar Pereiro with about a half mile to go in the 95.4-mile stage in the Massif central mountains of central France.

Guerini, who rides for the German T-Mobile squad, covered Friday's hilly route from Issoire in 3 hours 33 minutes 4 seconds. Armstrong's group, which included Basso, Rasmussen and other leading riders, came in 4:31 later.

The stage win was the second of Guerini's Tour career. In his first, up the legendary Alpine climb to the Alpe d'Huez ski station in 1999, he recovered and won after smashing into a fan who was trying to get a photograph of him from the middle of the road. Guerini fell to the ground. The spectator picked him up and pushed him on his way.

"This was less dangerous than L'Alpe d'Huez," Guerini said.