World champion Carmelita Jeter set the pace in Friday’s qualifying races for the women’s 100m sprint, running her heat in 10.83 seconds.
Jeter’s time was the fastest of all preliminary heats. She was followed closely by Blessing Okagbare of Nigeria, who is one of the other favorites for gold.
Also advancing to Saturday’s semifinals were Americans Allyson Felix and Tianna Madison, along with defending gold medalist Shelly-Ann Fraser-Pryce of Jamaica. Her teammates Veronica Campbell-Brown and Kerron Stewart, who won silver in Beijing, made it to the semifinals as well.
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The American team is trying to save face this year after the Jamaicans swept the field in Beijing in 2008.
The finals will be held Saturday at 4:55 pm ET.
The most disappointing finish in the 100m came from 17-year-old Noor Hussain Al-Malki of Qatar, who was among the first women sent by her country to the Olympics. Dressed in long sleeves, full leggings and a headscarf, Al-Malki made it just 15 meters before collapsing on the track and grabbing her leg. She was helped off the track by medics.
Elsewhere at Olympic Stadium on Friday, USA's Sanya Richards-Ross qualified for the 400m semi-finals on a track that had just been doused by a powerful downpour. Her time of 51.78 was nearly a second behind Christine Ohuruogu, a crowd favorite from London's East End, who ran neck-and-neck with Richards-Ross in Beijing in 2008 before passing her for the gold. Both were beaten by American Francena McCorory, who finished her debut Olympic race in 50.78 seconds.
With her hometown crowd cheering her on, Britain’s Jesssica Ennis took an early lead in the women’s heptathlon, finishing the first four events with 4,158 points. She was followed by Austra Skujyte of Lithuania and Jessica Zelinka of Canada. American Hyleas Fountain, who won silver in 2008, was fifth with with 3,900 points. Competition continues Saturday in the final three events: long jump, javelin and the 800m.
Reigning Olympic champion Tirunesh Dibaba of Ethiopia crushed her competition in the women’s 10,000m, finishing in 30 minutes 20 seconds -- 6 seconds ahead of silver medal winner Sally Jepkosgei Kipyego of Kenya. Another Kenyan, Vivian Jepkemoi Cheruiyot, won bronze.
American Reese Hoffa won bronze in the shot put, placing behind Tomasz Majewski of Poland and David Storl of Germany.