BOURG-SAINT-MAURICE, France — Alberto Contador rode hard to keep the Tour de France’s yellow jersey in the Alps on Tuesday, while teammate Lance Armstrong produced a dazzling burst of speed to remain in second place.

Mikel Astarloza of Spain won the 16th stage, a 99-mile route from the Swiss town of Martigny to Bourg-Saint-Maurice. Contador and Armstrong finished in the main pack behind Astarloza and other breakaway riders.
Contador, the 2007 Tour winner from Spain, fought off an attack led by brothers Andy and Frank Schleck of Luxembourg in the day’s second big climb.
“We had expected (an attack) and I gave my maximum. I could resist but not without difficulty,” Contador said. “I’m happy after this difficult day.”
Astarloza, who rides on the Euskadi Euskaltel team, thrust his fists in the air and kissed his fingers as he crossed the line in 4 hours, 14 minutes, 20 seconds. He was six seconds ahead of French riders Sandy Casar and Pierrick Fedrigo. The three-week Tour ends Sunday in Paris.
With a little more than a mile to go Tuesday, Astarloza escaped three other breakaway riders with him and held for his first Tour stage win.
“I was lucky to leave alone and finish alone,” Astarloza said. “I’m a complete rider but I’m not good at the sprint, so I have to attack from far away. This is the biggest day of my career.”
Contador, Armstrong, fourth-place Astana teammate Andreas Kloeden and third-place Bradley Wiggins of Britain all crossed 59 seconds after Astarloza.
Overall, Contador leads Armstrong by 1:37. Wiggins is third, 1:46 back, while Kloeden is 2:17 behind and Andy Schleck is fifth, trailing by 2:26.
With nearly 23 miles left, Andy Schleck attacked. He was quickly joined by Contador and a few other riders, but not Armstrong.
The 37-year-old Texan had dropped back by as much as 35 seconds. He then showed great speed to return to that small group of favorites, which included Schleck, Contador and Wiggins.
“I just didn’t want follow that quick acceleration like I tried to do on Verbier” — the first Alpine stage on Sunday, Armstrong said. “I’ve stayed with the other group, and then I realized the race was basically going away from us.
“So, I had no choice other than trying to make the cross,” Armstrong said. “So I waited until we had a steeper section and then I got away with an acceleration.”
Contador was impressed.
“It’s easy to explain — he’s a very great rider,” the Spaniard said. “He was in the past, and he showed it once again.”
Two-time runner-up Cadel Evans of Australia, who finished 3:55 back, was one of the big losers on the day. He fell to 17th from 14th and now trails Contador by 7:23.
The course ended with a 19-mile downhill run. Downhills make it hard for breakaway riders to outpace the fast-moving pack.
Riders scaled the highest peak of this Tour, the snowcapped Grand-Saint-Bernard pass on the Swiss-Italian border that is 8,113 feet. Its sister, the Petit-Saint-Bernard pass on the Italian-French border, was the day’s other big climb, and each was at least 13› miles.
The final descent was perilous: Jens Voigt of Germany crashed either from a bicycle malfunction or a bump in the road. The Tour’s medical staff said he severely bruised his face and right elbow, and was flown by helicopter to a hospital in the French city of Grenoble.
“He lost consciousness for a while, but he should be OK,” CSC team manager Bjarne Riis said. “For me, it’s a good sign.”
During the stage, an Astana vehicle was stopped and searched by customs officials at the Swiss-French border, the team said, adding nothing of concern was found.
Pope Benedict XVI sent greetings to Tour riders and organizers as the pack passed close to the Alpine retreat of Les Combes, overlooking Mont Blanc, where the pontiff is staying.
Wednesday’s stage features what some riders fear is the toughest Alpine route this year — a 105-mile ride from Bourg-Saint-Maurice to Le Grand-Bornand marked by five tough climbs and another downhill finish.