London: The United States struck triple Olympic track gold, while Usain Bolt kept alive his dream of an unprecedented second consecutive sprint double. Felix, a silver medallist at the 2004 and 2008 Games over the distance, powered to victory in 21.88sec to thwart Jamaican rival Shelly-Ann Fraser-Pryce's hopes of adding the 200m title to her 100m crown. (Agencies)
The American gold rush was fired by Allyson Felix in the 200m on Wednesday as she finally nailed an Olympic gold at the third time of asking.
Fraser-Pryce took silver in 22.09sec with Carmelita Jeter of the United States winning bronze in 22.14sec.
Jamaica's Veronica Campbell-Brown -- chasing a historic third consecutive Olympic 200m gold after pipping Felix at the two previous games -- had to settle for fourth in a time of 22.38sec.
"Finally! It has been a long time coming," said 26-year-old Felix. "I've waited so long for this moment, for so long, and I am just overjoyed.
"I thought back to the disappointment in Beijing. It's been a long road, I never wanted to give up. It's been a journey - never easy, but you can't lose sight of your dream."
Felix's gold was swiftly followed by a dominant display in the 110m hurdles by teammate Aries Merritt, the fastest man in the world this season.
Merritt clocked a personal best of 12.92sec, with another American, world champion Jason Richardson, taking silver, and Hansle Parchment claiming a surprise bronze -- Jamaica's first ever medal in the event.
Cuba's defending champion Dayron Robles failed to finish the explosive race after clipping a hurdle that left him clutching his leg in anguish.
"The gold medal means everything," Merritt said. "The US haven't had a gold medal (in the 110m hurdles) since Allen Johnson in 1996. It's phenomenal. To be here in this atmosphere is really special."
A third gold followed when two-time world champion Brittney Reese wrapped up the women's long jump, her best of 7.12m enough to see off Russian Elena Sokolova (7.07m), with American Janay Deloach taking bronze with 6.89m.
The other final of the evening session saw Russia's Natalya Antyukh win the women's 400m hurdles in 52.70sec ahead of American world champion Lashinda Demus and the Czech Republic's Zuzana Hejnova.
Bolt, the newly crowned 100m champion, moved to within one win of surpassing Carl Lewis' record of three golds and a silver in the sprints at the 1984 and 1988 Games when he progressed smoothly into Thursday's final.
"That is why I am here, to cement my legendary status. I am focused and I am ready," Bolt said.
He suggested that the final could well see his world record of 19.19sec tumble.
"It's a possibility, definitely. I can't say but the track is fast, it's going to be a good race."
Another runner aiming for a double is Britain's Mo Farah, who won the 10,000m on Saturday.
The Somali-born, London-raised Farah safely negotiated his passage into Saturday's 5000m final after a bumpy heat he compared to "being in the ring".
"There was lots of pushing and shoving so it was just a matter of staying out of trouble, but that's what happens in the heat. The final will settle down," Farah said.
South African star Caster Semenya, who was barred from the track for almost a year after tests into her gender following her win at the 2009 world championships, moved a step closer to adding the Olympic title to that crown as she eased into the 800m semi-finals.
"It was a tactical race. I wanted the race to be a fast one," she said of her heat, adding that her chances of winning a medal would come down to the speed of the race.
"I have to run a sub-two minute race to be a contender."
American world record holder Ashton Eaton dominated the first day of the decathlon, sitting on 4,661 points after the first five events, in three of which (100m, long jump and 400m) he set leading marks.
His overnight mark was 220pts more than US teammate and current world champion Trey Hardee (4,441), with Canada's Damian Warner in third on 4,386.
The gruelling 10-discipline event ends with the 110m hurdles, discus, pole vault, javelin and 1500m on Thursday.
London: The United States struck triple Olympic track gold, while Usain Bolt kept alive his dream of an unprecedented second consecutive sprint double.
Felix, a silver medallist at the 2004 and 2008 Games over the distance, powered to victory in 21.88sec to thwart Jamaican rival Shelly-Ann Fraser-Pryce's hopes of adding the 200m title to her 100m crown.