Digne-les-Bains, France ? Not everything went according to plan for Lance Armstrong on Thursday at the Tour de France.

The American retained his overall lead on the last of three days in the Alps. The loss of Manuel Beltran, however, could be critical in the upcoming Pyrenees.

David Moncoutie won the 12th stage, becoming the 15th Frenchman since World War II to win on Bastille Day, France’s national holiday.

Beltran, one of several riders Armstrong relies on to lead him up the Tour’s brutal climbs, touched wheels with another racer and crashed on the day’s first ascent, hitting his head. He was so dazed he didn’t know where he was.

“He was asking, ‘Where is the peloton? Where is the peloton?'” said team manager Johan Bruyneel, adding the Spaniard gingerly picked himself up off the sun-baked tarmac.

Beltran, who goes by the nickname “Triki” and has been part of Armstrong’s Tour-winning team since 2003, remounted his bike with difficulty and pedaled on for about six miles until a race doctor said he should stop, Bruyneel said.

Tour de France doctors tend to Spain's Manuel Beltran after he fell during the 12th stage of the cycling race. Beltran, a key member of Lance Armstrong's Team Discovery Channel, fell during the stage Thursday between Briancon and Digne-les-Bains, France.

“We could see that he really didn’t know where he was. There was no power at all, and after a while he didn’t even realize that he had crashed,” Bruyneel said. “So we forced him to stop.”

Beltran, 34, was taken to a hospital where a brain scan found no initial sign of serious injury, although he was being kept overnight for observation.

Not since 2001 has Armstrong finished in Paris without all of his teammates. Beltran’s role has been to lead the American on mountain ascents, using his uphill speed to shake off rivals.

His loss “could be very critical with the days that we have coming up,” Armstrong said. “Three tough days in the Pyrenees. We don’t want to lose any climbers, and Triki is one of our pure climbers.”

The mountains that separate France and Spain come Saturday after a mostly flat stage today from Miramas to Montpellier in southern France.

Armstrong still has several strong climbers among his remaining seven support riders. They include Yaroslav Popovych, who helped Armstrong leave rivals behind with brutal acceleration on the first Alpine stage, and Jose Luis Rubiera, known as “Chechu.”

“I feel very confident that with those seven guys we can manage,” Armstrong said.

Graphics give detailed info on stages 11 through 20 of the Tour de France; with related stories; 1c x various; 47 mm x various

Bruyneel was less emphatic.

“There is no one really who can pick up what he was doing,” Bruyneel said. “We need all the guys and everybody knows his role, and he and Chechu were working in the early mountains. It’s going to be tougher on the team of course, because it’s one guy less and his job will have to be shared with a few guys.

“It’s tough to lose a rider, but the good news is that he doesn’t have anything serious and that is the most important.”

Moncoutie took the lead on the Col du Corobin, the fourth of five ascents on the 116.2-mile trek from Briancon, and cycled alone into Digne-les-Bains past cheering crowds. The Cofidis team rider completed the route in 4 hours, 20 minutes, 6 seconds.

“It’s fabulous,” Moncoutie said. “I’m so happy to win. It’s July 14th.”

Armstrong cruised in with his main rivals in a group more than 10 minutes back. Armstrong was 41st.

His 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.

Italian Ivan Basso remains 2:40 back, fourth overall, with Jan Ullrich of Germany 4:02 behind in ninth.