Lance Armstrong (search) lost two seconds of his lead over rival Jan Ullrich (search) Friday in the Tour de France's (search) 18th stage, setting up a time-trial showdown for the title.

Ullrich, the 1997 champion and four times the runner-up, trimmed four-time winner Armstrong's overall lead to 65 seconds with two days left in the cycling marathon.

Ullrich earned a four-second bonus by finishing second in an intermediate sprint during Friday's 126.2-mile stage from Bordeaux to this town in west-central France. Armstrong was third in the sprint, picking up two bonus seconds.

With the overall standings so tight, the two seconds Ullrich gained could be crucial. At the least, they could give him a morale boost ahead of the time trial.

"It's not important losing two seconds. I don't think the Tour will be decided by two seconds," Armstrong said.

Pablo Lastras of Spain finished first in the stage at an average speed of 30.962 mph, making it the second-fastest road stage in Tour history. He completed the course in four hours, three minutes, 18 seconds.

Armstrong and Ullrich finished in a large pack of riders 24 minutes, five seconds behind Lastras, saving energy for Saturday's crucial race against the clock to Nantes.

Armstrong is trying to join Miguel Indurain (search) as the only riders to win five straight Tours. Never has Armstrong been locked in such a tight chase for overall victory.

Indeed, this year's race brings to mind Greg LeMond's stunning win by just eight seconds over Laurent Fignon in 1989 -- the closest finish in the Tour's 100-year history.

"This Tour could be decided by hundredths of a second, the thickness of two tires," said five-time winner Bernard Hinault.

The Tour ends Sunday in Paris with what traditionally has been a ceremonial ride -- but could become a finishing sprint to the title between Armstrong and Ullrich.

First, though, comes Saturday's 30.4-mile race from the Atlantic coast port of Pornic to the western town of Nantes. The flat course should suit both riders.

"Flat, straight, not technical, should be a tail wind ... could be very fast, could be one of the fastest time trials in Tour history," Armstrong said.

Ullrich, the silver medalist in the time trial at the 2000 Olympics, hopes to repeat his impressive defeat of Armstrong by more than 1 minute in last week's time trial.

Armstrong, however, was dehydrated during that stage because of a heat wave. He never has lost the closing time trial at the Tour since his first win in 1999 and says he has no intention of doing so this year.

"I'm relaxed," the 31-year-old Texan said. "I remain confident because I've raced very well in the last time trial over the last four years."

His mood has been more buoyant since his dramatic stage victory Monday in the Pyrenees, when he recovered from a fall and powered past Ullrich to build on his overall lead.

"He is confident," Armstrong's team director, Johan Bruyneel, said Friday. "He's happy, his morale is good. I think he'll do a good time trial."

Lastras outsprinted Carlos Da Cruz of France in the last few yards. Daniele Nardello of Italy was third.

"It was a very difficult stage, because it was very fast," said Lastras, of the Ibanesto.com team. "I wanted this victory for my mother, who died four months ago."