Levi Leipheimer moved ahead over the final metres to win the seventh stage of the Tour of California on Saturday while fellow American Chris Horner eased up at the line with the overall title within his grasp.
Leipheimer, a three-time Tour of California champion, began the stage in second place and still trails his team mate Horner by 38 seconds after winning his first career road stage in the race.
American Tom Danielson is third overall, trailing by two minutes 45 seconds.
"Barring anything catastrophic happening, I don't see much chance of losing the (race) leader's jersey tomorrow," said Horner, who last year finished 10th as the leading American in the Tour de France.
Leipheimer and Horner, who has led the event since his mountaintop victory in Wednesday's fourth stage, broke clear of the leading pack with about three kilometres left in the 121.9 km (75.8 mile) road race from Claremont to Mt. Baldy.
The route included about 40 km of climbing and its finishing altitude was the highest stage ever held in the race.
The event will end on Sunday with the 132.4 km eighth stage on a course unlikely to allow large time gaps.
Along with three other riders, Horner and Leipheimer went to the front as the dwindling field approached the final 10 km and the finish at Mt. Baldy, an elevation of 1,959 metres.
With about three km left, Horner and Leipjheimer surged ahead and quickly established their winning margin.
The two team mates clasped hands right after the finish, acknowledging Leipheimer's win and Horner's likely race title on Sunday.
"Our team was perfect today and you don't see that much in professional sports," said Leipheimer, who with Horner rode behind several team mates until the difficult concluding stretch of the race.
"There wasn't a lot of communication. Everyone just knew what the other was doing."