LONDON — Dawn Harper probably smiled more Tuesday as an Olympic silver medalist than she did as a champion four years ago at Beijing, when she was 24 and the 100-meter hurdle title landed in her lap after teammate Lolo Jones stumbled.

Her knees scarred but her spirit intact, Harper battled Australia's Sally Pearson as hotly as the flame in the Olympic Stadium caldron. Pearson needed an Olympic-record time of 12.35 seconds to edge past Harper's personal-best 12.37 performance, with Americans Kellie Wells and Jones close behind at 12.48 and 12.58, respectively.

Two years after she had knee surgery and a doctor said she might never hurdle again, Harper achieved a new excellence and a perspective that made her second-place finish feel like a triumph.

"To go from that to this ... there were many times I broke down crying," said Harper, who trains in Los Angeles. "I was like, 'Lord, this is what you see for me.' I thought I had a gift."

Pearson, the Beijing silver medalist, initially wasn't sure of the outcome. "I thought I won and looked to my left and thought maybe I didn't. It was really quite close," she said. "When I saw my name on the scoreboard at No. 1, it was a dream come true."

Surprisingly, American athletes proved as good at long races as the sprints and hurdles. Leonel Manzano of Marble Falls, Texas, finished second in the 1,500, the first American man to win a medal in that race since Jim Ryun won silver in 1968. And Nick Symmonds and Duane Solomon Jr. qualified for the 800 final, the first time the U.S. has had two finalists since 1992.

Coupled with Galen Rupp's silver in the 10,000, this is the first Olympics since 1968 in which U.S. men have won two medals at distances of 1,500 meters or more.

Taoufik Makhloufi of Algeria, who was expelled from the Games for not going all-out in his 800-meter heat but was later reinstated, won the 1,500 in 3 minutes 34.08 seconds. Manzano, who surged from sixth to second in the last 150 meters, finished in 3:34.79.

"That was the first time I've ever cried on a track. That's stronger than words, I guess," Manzano said.

Erik Kynard of Toledo, Ohio, cleared 7 feet 7 ¾ inches in the high jump to win a surprise silver medal.

Jamaica's Usain Bolt eased through the first round of the men's 200, jogging to the finish line in 20.39 seconds.