BEIJING — Defending champion Liu Xiang pulled up lame and withdrew from the first round of the Olympic 110-meter hurdles race today, leaving the host country without one of its biggest stars.

Liu, whose hamstring has been an issue for months, limped out of the block at the starting gun, took a few awkward steps, then pulled up when the second gun sounded to signal a false start.

That false start did not disqualify anybody. Liu nonetheless tore the number off his leg, turned around and walked into the tunnel, his Olympic hopes — and the great hopes of his country — dashed before he ran a single race.

"It's a shame," said Wu Fan, a Chinese woman speaking in the Chaoyang district of east Beijing. "He was the focal point for China."

Liu's image is plastered on advertising billboards all over the country. His renown grew in part because he was the first Chinese athlete to win in an event that had been utterly dominated by westerners.

"We worked hard every day, but the result was as you see, and it's really hard to take," Liu's personal coach, Sun Haiping, said at a news conference the hurdler did not attend.

Sun, who paused to wipe away tears while answering questions, said Liu was bothered by a right foot injury that has lingered for six or seven years — and not the right hamstring that has dogged him for months. The foot pain intensified Saturday.

News of the injury spread fast among Chinese fans, who were intently focused on the race. In Beijing, 10 employees at a picture-frame shop across from the National Art Museum of China huddled around a computer screen to watch the heat.

"The greater the expectations, the greater the disappointment," said Lu Fei, the 53-year-old shop manager, after Liu pulled out.

Cui Xiaohuo, a sports reporter for China Daily said: "It's hard to believe. I think the injury is still bothering him. I didn't think this would happen. I thought Liu Xiang might lose to Robles, but I never thought that he would be out of it before he even ran the first race."

TRIATHLON

BEIJING — Emma Snowsill of Australia has won the Olympic women's triathlon, pulling away toward the beginning of the 10-kilometer run to finish over a minute ahead of the field. Vanessa Fernandes of Portugal won the silver, and Emma Moffatt of Australia came across the finish line about 20 seconds later for the bronze.

GYMNASTICS

BEIJING — Romania's Sandra Izbasa — the very last competitor — grabbed the floor exercise gold away from American Shawn Johnson yesterday. America's Nastia Liukin got bronze in the event. China's Cheng Fei lost for the first time in three years in women's vault. North Korea's Hong Un Jong won it. American Alicia Sacramone was fourth. China dominated the men's event finals, with Zou Kai winning the floor exercise and Ziao Qin taking pommel horse. Counting team and all-around, the hosts are 4 for 4 in men's events.

TENNIS

BEIJING — Rafael Nadal becomes No. 1 in the world today. He'll also wake up an Olympic champion. Nadal overcame two set points in the second set and held every service game to beat Chile's Fernando Gonzalez 6-3, 7-6 (2), 6-3 yesterday. The Williams sisters won the women's doubles title by romping past Spain's Anabel Medina Garrigues and Virginia Ruano Pascual 6-2, 6-0. They also won in Sydney. In women's singles, Russia became the first nation to sweep a tennis event since Great Britain in 1908 women's singles. (Note that tennis was not a medal sport between 1924 and 1988.) Elena Dementieva beat Dinara Safina 3-6, 7-5, 6-3, and Vera Zvonareva beat Li Na of China 6-0, 7-5 for the bronze.

FENCING

BEIJING — After missing out on a medal four years ago because of consecutive 45-44 losses, Keeth Smart and the U.S. men's saber team got to the gold-medal bout with a pair of 45-44 victories. But they couldn't get past the French in the finals. Still, Smart, Tim Morehouse and James Williams celebrated the silver. "It's been four long years of heartache that we've had to relive over and over," said Smart.

WOMEN'S BASKETBALL

BEIJING — Tina Thompson scored 10 points during a 21-0 run, sending the U.S. women past New Zealand, 96-60, yesterday. The Americans went 5-0 in pool play, winning by an average of 43 points.

SOFTBALL

BEIJING — The U.S. women won their 20th straight Olympic game yesterday. Monica Abbott pitched five perfect innings and Crystl Bustos, Jessica Mendoza and Tairia Flowers homered in an 8-0 victory over the Netherlands.

BOXING

BEIJING — The Americans won't be going home empty-handed, thanks to heavyweight Deontay Wilder getting to the semifinals, assuring him of at least bronze. "I don't want the world to remember Team USA as being failures," Wilder said. The only other U.S. boxer left, Demetrius Andrade, was ousted by South Korea's Kim Jung-joo, a bronze medalist in Athens.

BEACH VOLLEYBALL

BEIJING — There won't be an all-American women's finals. Elaine Youngs and Nicole Branagh were ousted with a loss to a Chinese team yesterday. Earlier, Americans Kerri Walsh and Misty May-Treanor advanced to the final four with a straight-sets victory over Brazilians Ana Paula and Larissa. Today, Americans Todd Rogers and Phil Dalhausser are in the men's final four after beating Germany 21-13, 25-23.

ROWING

BEIXIAOYING TOWN, China — The U.S. women eight took gold and the U.S. men eight took bronze. Canada won the men's eight, becoming the first world champion crew to follow up with Olympic gold in 35 years. China won its first-ever rowing medal in women's quadruple sculls.

SAILING

Qingdao, China — In strong winds, heavy waves and rain, Britain's Finn sailor Ben Ainslie won his third Olympic gold medal and American Zach Railey got silver, shortly after a trio of British women took the Yngling sailing gold.