The four-time champion prepares for the grueling mountain stages.

NEVERS, France (AP) – Lance Armstrong finished 53rd in the fifth stage of the Tour de France on Thursday and remained second overall behind U.S. Postal Service teammate Victor Hugo Pena.

With the race moving into the mountain stages this weekend, Armstrong, trying for a record-tying fifth straight Tour win, chose to avoid the risk of riding up front with the sprinters.

Alessandro Petacchi, considered the sprint king of this Tour, won for the third time in five stages, making light work of the fierce final dash.

He beat Jaan Kirsipuu of Estonia and Australian Baden Cooke to the line at Nevers with a burst of speed in the last several hundred yards.

Petacchi thrust an arm into the air in a victory salute as he crossed the line.

Pena celebrated his 29th birthday by retaining the overall leader’s yellow jersey, finishing 63rd in the stage.

“It’s the best birthday present I’ve had,” he said.

Petacchi, of the Italian Fassa Bortolo team, completed the 121.8-mile leg from Troyes in 4 hours, 9 minutes and 47 seconds.

Petacchi also won the first and third legs of the 20 stage race.

In Wednesday’s fourth stage – a 42.8-mile team time trial from Joinville to Saint-Dizier – Armstrong and his teammates blew the competition away, recording their first ever win in the speed and teamwork-orientated discipline.

Armstrong, closing in on Spaniard Miguel Indurain’s record of five straight Tour victories, is peaking at the right time – with the mountain stages lying in wait.

“I had some problems before the Tour that I didn’t elaborate on,” Armstrong said after the win.

“I didn’t talk about them because it’s really not important. But I’m getting better. I feel better every day.”

With the Postals hogging the top eight places in the overall rankings after the fourth stage, Armstrong and his teammates are in great shape to tackle the next five stages.

The danger has almost passed for Armstrong – fortunate not to be seriously hurt in Sunday’s first stage when the Texan was among around 35 riders caught in a pileup.

Friday’s sixth stage sees the first noteworthy climb. Riders must tackle the Cote des Echarmeaux – which peaks at 2,336-feet – before arriving in Lyon.

Saturday’s 140.12-mile haul from Lyon to the ski resort of Morzine-Avoriaz is the first of three days of alpine ascents.

After several medium-difficulty ascents, the riders face two mammoth climbs in the last 12.4 miles of the stage.

The Col de la Ramaz, which peaks at 5,343 feet, is followed by a 3,897-foot ascent on the Cote des Gets. A downhill dash then carries tired limbs to the finish line.

“I’m feeling better and better,” Armstrong said, adding that a modest seventh-place finish in Saturday’s prologue and Sunday’s first-stage crash had dampened his spirits.

“Definitely the prologue wasn’t sharp, but in light of the way I was feeling after the first stage I shouldn’t be surprised that I’m feeling better now,” Armstrong said.

As the Postals crossed the finish line Wednesday, they immediately dismounted and then screamed in delight as a swarm of spectators, some waving U.S. flag, engulfed them.

Armstrong’s American teammates, George Hincapie and Floyd Landis, jumped into each others arms.

“It was perfect, as good as you can ask for,” Landis said. “The course was difficult, as you had a head wind. But we have big strong guys. They’re not all the best time-trialers in the world, but when you put us all get together it’s good enough.”

Pena took the yellow jersey awarded to the Tour’s overall leader because he was a second faster than Armstrong in the prologue, a sprint through Paris last Saturday.

Pena is the first Colombian to have earned the jersey in the Tour’s 100-year history.

AP-ES-07-10-03 1146EDT