BEIJING — Far ahead halfway through his 100-meter Olympic quarterfinal, Usain Bolt casually swiveled his head to his right, to his left, then back to his right.

Never hurts to check. No one was nearby — hardly surprising, given how quickly the 6-foot-5 Bolt's long strides carried his golden spikes. So the world record-holder slowed to what for him amounts to a jog.

He still crossed in 9.92 seconds, a time that makes it the fastest dash ever run in China, a time that would have earned a medal at all but two previous Summer Games and a time that fails to reflect how effortless Bolt's performance was.

The Jamaican licked his lips, checked the scoreboard and pumped a fist, his untucked yellow sleeveless shirt rippling. The message, to himself and to rivals Asafa Powell and Tyson Gay, was unmistakable:

Bring on today's 100 semifinals and final.

"I just ran the first 50 meters, then I looked around to make sure I was safe, and I shut it off," Bolt said last night. "I'm ready for my best."

Goodness. Remember, this is a guy who said as recently as last week that he wasn't sure whether he would race the 100 — an event he only began pursuing seriously this year — in addition to his specialty, the 200, at these Olympics.

"He's a phenomenal athlete," said Darvis Patton of the United States, who also advanced to the semifinals.

Bolt, his Jamaican teammate Powell and U.S. record-holder Gay — the reigning world champion who hadn't raced in 1 1/2 months because of a left leg injury — all advanced without a hitch through two 100 heats yesterday, when the 10-day track and field competition opened.

Today's first track and field medal went to Valeriy Borchin of Russia in the men's 20-kilometer walk. He finished in 1 hour, 19 minutes, 1 second — 14 seconds ahead of 1996 gold medalist Jefferson Perez of Ecuador. Jared Tallent of Australia won the bronze.

Today's schedule also included heats in the women's 100 and 400, along with medals in the women's shot put and heptathlon.

The first medal final yesterday, the men's shot put, was most foul for a U.S. contingent that was hoping for a sweep. Instead, the Americans settled for a silver from Christian Cantwell behind champion Tomasz Majewski of Poland, whose winning throw of 70 feet, 7 inches (21.51 meters) was more than three feet shy of the personal bests of all three Americans.

SOFTBALL

Turns out, the U.S. women are as dominant as ever. First they set an Olympic record with four homers in a 7-0 victory over Japan. Then they resumed a rain-stopped game against Canada, trailing 1-0. After being five outs from losing, they wound up winning by the lopsided score of 8-1. The Americans broke the game open with four runs in the sixth, helped by two errors by Canadian shortstop Jennifer Salling, and a wild pitch and hit batter by Dione Meier of Canada, which beat China 1-0 earlier in the day. In other games, Australia beat Taiwan, 3-1, and Venezuela beat the Netherlands, 8-0.

WOMEN'S BASKETBALL

The U.S. women started slowly, then got clicking, pounding Spain, 93-55. Tina Thompson scored nine of her 17 points during a game-breaking 20-5 run in the third quarter and Lisa Leslie added 14 points and 11 rebounds. With the win, the U.S. has 29 straight victories in Olympic games. The last loss was to the Unified team in the 1992 semifinals. In other games yesterday, Australia topped Latvia, 96-73; Russia edged Brazil, 74-64; the Czech Republic beat New Zealand, 90-59; China routed Mali, 69-48; and Belarus topped South Korea, 63-53.

TENNIS

An American won't win the men's singles title. James Blake, the last hope left, lost to Chile's Fernando Gonzalez, who blew four match points before winning 6-4, 5-7, 11-9. Gonzalez, seeded 12th, will play in tomorrow's final against Rafael Nadal, who beat Novak Djokovic, 6-4, 1-6, 6-4, to clinch his first Olympic medal.

New women's No. 1 Jelena Jankovic lost in the quarterfinals to No. 6 Dinara Safina, who will play China's Li Na in the semifinals. The other semi will pit Russians Elena Dementieva and No. 9 Vera Zvonareva.

In doubles, Roger Federer kept alive his hope for an Olympic gold medal, joining Swiss teammate Stanislas Wawrinka to upset top-ranked American twins Bob and Mike Bryan and win a spot in the final.

BEACH VOLLEYBALL

Americans Phil Dalhausser and Todd Rogers have advanced to the quarterfinals of the Olympic beach volleyball tournament, squeaking by Switzerland in three sets, 21-16, 21-23, 15-13. Heavy favorites to win the gold medal in their Olympic debuts, Dalhausser and Rogers have won three straight since their Beijing opening upset by the No. 23 seed from Latvia. The other U.S. men's team, Jake Gibb and Sean Rosenthal, played Spain later today.

SHOOTING

The Emmons family picked up another medal. This time, it was hubby Matt getting silver in the 50-meter prone, an event he won four years ago. His wife, Katerina, who shoots for the Czech Republic, has a gold and a silver from these games.

BOXING

Sergey Vodopyanov, the world champion bantamweight, and Raynell Williams, a serious American medal contender, lost last night, both saying they were wronged by subjective calls. Vodopyanov was edged by India's Akhil Kumar on total punches in a fight that ended 9-all, while Williams fell behind early and never caught up to France's Khedafi Djelkhir. China's surprising team has six boxers still in the tournament amid complaints from some fighters about judges favoring the home nation. Cuba kept nine boxers in with wins by lightweight Yordenis Ugas, bantamweight Yankiel Leon and featherweight Idel Torriente.

CANOE-KAYAK

Look out for the Slovaks on the whitewater course. Twins Pavol and Peter Hochschorner won their third straight gold medal in double canoe slalom and countrywoman Elena Kaliska won the women's single kayak slalom for her second straight gold in the event.

ARCHERY

When South Korean Park Kyung-mo got an 8 on his next-to-last shot, tying the finals, Ukraine's Viktor Ruban responded with a perfect 10. Park could've forced a shoot-off with a perfect score of his own, but he was a few millimeters wide, giving Ruban the gold.

WEIGHTLIFTING

China got its seventh and eighth gold medals in weightlifting, with Lu Yong winning the fourth by a man and Cao Lei taking the fourth for a woman. "We have proved our strength," Cao said. Kendrick Farris set two U.S. records in the men's 85-kilogram division, but had to settle for eighth place.

CYCLING

It was a big day for Britain, with the British beating France for the gold in men's team sprint and Bradley Wiggins setting an Olympic record in qualifying for the 4,000-meter individual pursuit. American Taylor Phinney — the 18-year-old son of 1984 gold medalist Connie Carpenter-Phinney and '84 bronze medalist Davis Phinney — advanced in the pursuit race with his parents watching from the front row.

JUDO

China's Tong Wen won a dramatic come-from-behind victory over Athens champion Maki Tsukada to take the women's heavyweight title and deny Japan a golden double on the final day of competition. Japan's Satoshi Ishii, making his Olympic debut, defeated Uzbekistan's Abdullo Tangriev to win the men's over 100-kg.

BADMINTON

Defending champion Zhang Ning of China won the gold medal in women's singles today, defeating teammate Xie Xingfang, 21-12, 10-21, 21-18. Maria Kristin Yulianti of Indonesia won the bronze medal, defeating Lu Lan of China, 11-21, 21-13, 21-15. China's Du Jing and Yu Yang won the women's doubles over a South Korean team. Another Chinese tandem got the bronze, beating a Japanese duo that knocked off the top-seeded, defending Olympic champions.