ANNECY, France — Alberto Contador all but assured his second Tour de France victory Thursday, winning the race’s final time trial while Lance Armstrong struggled with fatigue but moved up one spot to third place.

Contador, Armstrong’s Astana teammate and the 2007 Tour champion, increased his overall lead in the 18th stage in which cyclists rode against the clock on the 25-mile course in and around Annecy. The three-week race ends Sunday on the Champs-Elysees in Paris.
Contador finished in 48 minutes, 31 seconds, beating Fabian Cancellara of Switzerland by three seconds. Russia’s Mikhail Ignatiev was third, 15 seconds back.
“I went all out,” said Contador, adding his earpiece radio linking him to team managers stopped working during the stage and he was worried about Cancellara’s skill at time trials.
“Of course, what I especially wanted was to think about general class. A stage victory was less important,” he said. “I’m very happy. I didn’t expect it.”
Armstrong was 16th, 1:30 behind. But he easily overcame a 30-second deficit to Frank Schleck, who began the day in third place but slipped to sixth after finishing 2:34 behind Contador. Armstrong had “mixed emotions” about his ride.
“Sixteenth in a time trial is not a good result,” he said. “But my ambition is to get on the podium, so I have to be happy with that.”
Schleck and younger brother Andy had bumped Armstrong from second place to fourth a day earlier in the last punishing Alpine stage.
“I suffered,” Armstrong said. “I probably started too hard and maybe I was just empty from yesterday and those cramps I suffered at the end of the (17th) stage.”
Afterward, Armstrong announced that he and Radio Shack are forming a new team that will compete in next year’s Tour. Armstrong came out of retirement this season to ride for the Kazakh-funded squad headed by his longtime mentor Johan Bruyneel, who led him to his seven straight Tour wins.
Overall, Contador leads Andy Schleck by 4:11. Armstrong is 5:25 back and Britain’s Bradley Wiggins is fourth, 5:36 behind. Germany’s Andreas Kloeden, another Astana rider, is fifth, 5:38 back. Frank Schleck is sixth, 5:59 behind.
While the stage was mostly flat, riders had to contend with the Bluffy pass climb, which snaked upward for more than two miles with magnificent vistas over the hill-ringed lake. Several riders, including British time-trial specialist David Millar, said the layout favored climbers because of that ascent.
“I felt like I had stopped dead in my tracks,” Millar said.
The race started under cloudy skies as riders went one by one down the start ramp. The sun eventually broke through, but rain doused the course by late afternoon and left patches of water on the roads.
Armstrong was relatively strong at the start, only 29 seconds slower than Contador through the second intermediate time check at the 25-kilometer mark. His main time deficit came on Bluffy, where he was 1:12 behind Contador.
“I felt good at the beginning, I felt smooth,” he said. “But there was a tail wind, so maybe everyone felt good. I just wasn’t that strong on the climb.”
After four straight tough stages, riders get a relatively easier trip Friday, a 111-mile course from Bourgoin-Jallieu to Aubenas. The biggest challenge left is an uphill finish at Mont Ventoux on Saturday, a day before the finish.
The threat for Armstrong is again likely to be the Schleck brothers.
“I want to protect my position with Andy climbing so well,” Armstrong said, “Just got to watch for the moves and don’t let him get away.”