Kristin Armstrong is bringing a gold medal back to Boise.

The Boise cyclist won the Olympic women's time trial late Tuesday night outside of Beijing, using a dominant effort in the second half of the race to overtake Britain's Emma Pooley.

Armstrong finished the 15-mile course in 34 minutes, 51.72 seconds. Pooley, who led Armstrong by nearly four seconds at the 6.7-mile mark, finished in 35:16.01, more than 24 seconds off Armstrong's pace.

"It was the greatest day of my life," said Armstrong, who began crying while hugging husband Joe Savola after the race.

Armstrong fought back tears on the medal stand as the American flag was raised.

"I've been working the last eight years for this and to have everything go right on one day," she said after the race. "To me, the Olympic gold medal is the reward."

Armstrong, who turned 35 on Monday, went to China in December to ride the course. She programmed the course into her GPS, then used that to recreate it and train back in Boise. Armstrong practiced climbing on her time trial bike in anticipation of the event.

All those miles climbing Bogus Basin Road paid off Tuesday.

"I knew I had to learn the climb on my time trial bike to win today," she said after the race.

Unlike Sunday's road race, in which Armstrong finished 25th in heavy rain, the weather was hot and humid for the time trial. Armstrong was the 20th of 25 riders to begin the event with each beginning two minutes after the previous one.

Armstrong passed two riders on the course in becoming the second American woman to win an Olympic cycling gold. Connie Carpenter-Phinney won the road race at the 1984 Games in Los Angeles.

"She was very, very nervous (before the race), but you could tell she felt good," Savola told the Statesman in a phone call after the race.

Savola, too, got nervous when the split time showed her more than 3.5 seconds behind Pooley, but well ahead of the other competitors.

"Being almost four seconds down, there's not a ton of time to be made up on downhill," he said.

But Armstrong made it up - and then some.

Savola snuck around the course, using his passport and wedding band to persuade officials to let him watch from the Great Wall and the media area.

He was in the media area after the race when he found Armstrong.

"It was beautiful," Savola said. "It was great. I think that's when she got pretty emotional."

Switzerland's Karin Thurig finished third. France's 49-year-old Jeannie Longo-Ciprelli placed fourth. Armstrong's teammate Christine Thorburn was fifth.

NBC is scheduled to air portions of the time trial during Wednesday's primetime telecast. Armstrong is expected to return to Boise on Friday.

A former triathlete, Armstrong took up competitive cycling in 2001. She qualified for the 2004 Olympics and finished eighth in the road race.

Armstrong did not ride in the time trial in those Games, but soon after became a dominant competitor in the event. She finished third in the 2005 world championships, took the title the next year and finished second in 2007.

One of the favorites entering these Olympics, Armstrong planned her entire year around peaking for this event - even scheduling her November wedding to Savola and honeymoon around her training routine.

Armstrong got her athletic start at age 7 when she went with older brother Eric to compete for a local swim team in Naples, Italy. Armstrong's father, Bill, was a colonel in the Marines, so a young Kristin lived in Italy, Japan and the U.S.

She swam for her high school team in Japan and returned to the U.S. to attend the University of Idaho. She did not compete in any sports for the Vandals.

Armstrong moved to Boise in 1995 after college and took a job with the YMCA.

She eventually competed in the Y-Not-Tri triathlon in Boise and became so good at the sport that she earned a spot on the 1999 USA Triathalon Resident Team and a spot in the 2000 Olympic Trials.

A foot injury derailed her, and in 2001, Armstrong was diagnosed with osteoarthritis in both hips.

She began cycling instead, racing in the Women's Challenge, a stage race in Idaho. From there, Armstrong's cycling career blossomed and she quickly climbed the professional ladder in the sport.

That ascent culminated Tuesday night - with a gold medal around her neck and tears in her eyes.