American Levi Leipheimer maintained his race lead on the sixth and final stage of the USA Pro Cycling Challenge from Golden, up Lookout Mountain and down through Denver in front of the state Capitol, winning the yellow jersey in the 518-mile race’s inaugural year.

Daniel Oss of Liquigas-Cannondale won Sunday’s 70.9-mile stage in a final sprint down Broadway in 2 hours, 27 minutes, 8 seconds. His teammate, Elia Viviani, who had won the two previous stages, finished second and captured the race’s green sprint leader jersey.

“It’s hard to put into words to describe the emotion and the experience I’ve had this week,” Leipheimer of Team Radioshack said. “When I was 13 years, I watched the Tour de France on television and read magazines about the Coors Classic. And now to be here 25 years later and to experience the size and scope of this race is beyond my expectations. I really didn’t expect this many people to come out to this race.”

Race organizers and cyclists agreed that the final day summoned the largest crowds ever for a cycling stage on American soil — nearly 250,000 people Sunday with more than 1 million people overall for the week-long event, officials said. The 70.9-mile stage began late Sunday morning near the foothills in Golden, circling the town before turning up the windy road up Lookout Mountain, where thousands of fans turned out to line the punishing but iconic route pedaled by numerous cyclists each year. The stage route continued along the avenues and boulevards of Denver, where cyclists completed five laps once reaching downtown.

Leipheimer’s final time for was 20:00:24. Christian VandeVelde of the Boulder-based Garmin-Cervelo squad was second, 11 seconds behind Leipheimer; Tejay Van Garderen (HTC-Highroad) finished third, :17 back; Boulder’s Tom Danielson (Garmin-Cervelo) was fourth at :21; and George Hincapie (BMC Racing) was fifth at :53. All of the top five finishers in the field, which included this year’s Tour de France podium, were American.

“This victory means so much to me,” Leipheimer said, “mainly because of the way we (Team Radioshack) raced this week. It took some of the best form of my life to beat Christian and Garmin-Cervelo and Tejay. I took the jersey and lost the jersey, and I had to produce one of the best time trials of my life to take it back. Then the team rose to the occasion to defend that jersey against a super-motivated home squad of Garmin-Cervelo. It took every ounce of energy and motivation to pull it off.”

Leipheimer’s victory in Colorado marked his third major race win so far this season after a crash ended his hopes of a successful Tour de France. He won the Tour of Switzerland by four seconds in June, then took the Tour of Utah a few weeks ago.

Australian Cadel Evans (BMC Racing) arrived in the U.S. for the USA Pro Cycling Challenge with ambitions but no great expectations just weeks after winning his first Tour de France. Like many cyclists, the altitude made for grueling racing over the past seven days.

“I think the racing was very competitive, especially considering the altitude,” Evans said. “I don’t know if I’ve raced anywhere in my career where people were so appreciative of my being here. That’s not something that a race organizer can control, it’s just the ambiance of the race.”

The race began Monday in Colorado Springs with a 5-mile Prologue time trial from the Garden of the Gods to the city’s downtown. From there, riders traveled from Salida on an uphill finish into Mt. Crested Butte, the first day Leipheimer held the yellow overall leader’s jersey. Wendesday’s “Queen Stage” from Gunnison to Aspen sent riders over the two highest climbs in professional cycling history — the 12,000-foot peaks of Cottonwood and Independence passes that ended with Van Garderen, 23, claiming the overall lead after Leipheimer fell apart coming down Independence into Aspen. But Leipheimer’s years of experience and preparation paid off Thursday, when he rode an individual time trial in Vail, beating VandeVelde by 0.58 seconds and Van Garderen by more to reclaim the overall lead.

For VandeVelde, watching Leipheimer ascend Vail Pass and top his time was perhaps the most frustrating of the race, despite numerous foiled attempts to retake the lead later.

“Looking back, it was a hard week,” VandeVelde said. “I coulda, shoulda, woulda done a couple of things, especially going down (Independence Pass) with Tejay. That probably would have been the easiest way to win this race.

“Standing up here on the podium is great, but I still have the blood in my mouth for next year, that’s for sure,” VandeVelde said, smiling.

From Vail, Leipheimer and his Radioshack teammates never backed down, successfully covering attacks from Garmin-Cervelo to hold onto the overall lead into Sunday’s final stage.

“This is fantastic for us as American cyclists to come back and race on American soil,” Leipheimer said. “We’ve spent many years in Europe just toughing it out in the trenches. It’s just such a great feeling to come back and bring the sport to America on a scale this big.

Daniel Petty: dpetty@denverpost.com or twitter.com/danielpetty