LONDON (AP) -- Sally Pearson has the world's fastest female hurdlers on her tail and the weight of a country's expectations on her shoulders at the Olympics.
Australia is having its worst Olympics in decades, but Pearson showed Monday that she's desperate to come to the rescue.
Pearson won her opening race in the 100-meter hurdles in 12.57 seconds, the fastest time ever in a heat at the Olympics. She cleared every obstacle to advance but Jamaica's Brigette Foster-Hylton, one of her biggest threats, hit one so hard she is out of the games.
Pearson is world champion, IAAF athlete of the year, and has long been a favorite for gold. But little has gone right for the Australian team and, instead of being in the top five in the gold-medal standings, it was lagging in 24th place after the first week.
At least Pearson is heading in the right direction, demonstrating to a "stacked" field that she has only one intention in London.
American LoLo Jones has the second-quickest time in 12.68 and defending Olympic champion Dawn Harper also advanced.
Kenya's 800-meter world champion and record holder David Rudisha also showed the way forward, leading from start to easily win his heat later Monday. His rival, Abubaker Kaki of Sudan, had the top time in qualifying of 1 minute 45.51.
In the women's hurdles, Foster-Hylton took center stage, but for all the wrong reasons. She was supposed to add more medals for Jamaica's sprint juggernaut, but despite her experience she committed a basic error in her heat.
Going with the pace in the final heat, her trailing foot slammed into hurdle five of 10, and as well as she tried to regain momentum, she knew she was out of the games when she crossed the line.
She threw herself to the ground and screamed loudly, brushed aside Jones when she came over to console her and then slammed herself into the ground again. At 37, she knew she had wasted perhaps her last chance at an Olympic medal. The 2009 world champion had the second-best time of the year coming into the Olympics.
"I'm devastated for her," Jones said. "She's been so dominant. For her not to have an Olympic medal, my heart breaks for her."
Jones knows perfectly what it means, having gone from almost certain gold to a seventh-place finish when she stumbled over the penultimate hurdle at the Beijing Olympics final four years ago.
But words could do nothing for Foster-Hylton, as she rejected Jones. Pearson also came over to hug her.
"Even if she would have punched me, I totally would understand," Jones said. And with her voice cracking, added, "We work so hard for this."
For Pearson there is the added weight of national expectation. and she admitted to being "really nervous" before her race.
"I don't know, it's really bizarre," Pearson said. "I've never felt like I am now."
"Just nerves because it's the Olympic Games. Nerves because it's the first round of my event."
But she tried to reassure her supporters, saying she wouldn't be doing her job if she wasn't nervous.
In the women's 1,500, world indoor champion Genzebe Dibaba of Ethiopia failed to qualify when she finished 10th in her heat, clutching her left hamstring after falling to the ground beyond the line. The younger sister of 10,000 gold medalist Tirunesh Dibaba was taken off in a wheelchair.
World champion Jenny Simpson of the United States also struggled, having to come up with a mighty finishing effort to squeeze into the top-six in her heat.
In the women's shot put, defending champion Valerie Adams easily qualified along with Nadzeya Ostapchuk of Belarus, who had the best ever qualifying shot at the Olympics with 20.76 on her first attempt.
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