Top-seeded Paradorn Srichaphan is in doubt for the Asian Games singles tennis tournament after retiring with an injured wrist during the men's team quarterfinals Tuesday against Uzbekistan's Denis Istomin.

Thailand's Paradorn Srichaphan hits a forehand to Switzerland's Roger Federer during their semi-final match at the Swiss Indoors ATP tennis tournament in Basel October 28, 2006. [Reuters]

The Thai star lost the first set 3-6 and was down 0-2 after six minutes in the second set when he left the court.

"It's an injured tendon," Paradorn said. "It was hurting when I hit the ball.

"My doctor in Thailand told me to take a few weeks off from playing and I had very little time before coming here," he added. "There's no point risking it. I'm very disappointed. I might have to withdraw from the singles."

Paradorn, who has five career ATP titles and reached a career-high No. 9 on the men's professional tour eight months after winning the 2002 Asian Games gold medal, will speak with his team before deciding whether to compete in the singles tournament.

Istomin, an unknown wild card entry when he opened this year's Australian Open against top-ranked Roger Federer, and Murad Inoyatov lost the deciding team doubles in three sets later Tuesday to brothers Sanchai and Sonchat Ratiwatana of Thailand.

China won both time trials on the road cycling course.

Song Baoqing coasted to a comfortable win over Kyrgyzstan's Evgeny Vakker and women's defending champion Li Meifang was almost a minute faster than her nearest rival in the road cycling individual time trial.

Baoqing finished with a time of 53 minutes, 33.35 seconds on 44.8-kilometer (27.8-mile) Al-Kor on the Qatar coast north of Doha. Li won the women's race in 31:17.85, beating out Zulfiya Zabirova of Kazakhstanwon.

"The road feels good," Li said of the cycling course in the ancient fishing village. The surface of the road is very beautiful, and flat is good for the required result."

Choi Jun-sang won the individual dressage on Dancing Boy II for South Korea's second equestrian medal of the games, outriding Yukiko Noge of Japan and Malaysia's Qabil Mahamad Fathil.

Singapore claimed its first gold medal early Tuesday morning when Michelle Kwang Tien Mei and Valerie Teo Hui Ying combined to win the women's doubles bowling title.

The pair joins Bee Leg Tan to contest Tuesday's trios final.

Kazakhstan spoiled a Chinese sweep of the morning shooting competition, winning gold in the 10-meter running target team event, thanks largely to Rassim Mologly's silver medal effort in the individual division.

Rashid Yunusmetov earned another silver for Kazakhstan in the 50-meter pistol event, behind Wold Cup champion Xu Kun.

"I expected to do better," Yunusmetov said. "I'm very disappointed with the result in final round."

"I'm very surprised I still won the silver."

China's women won yet another weightlifting gold men when Cao Lei took the 75 kg class. Oo Mya Sanda of Myanmar was second and South Korea's Kim Soon-hee was third.

In baseball, Naoki Miyanishi pitched a complete-game, four-hit shutout and struck out 10 to lead Japan to a 6-0 win over Thailand.

Right fielder Kei Nomoto knocked in two runs and Japan scored four runs in the seventh inning to break open a close game.

The win moved Japan to 4-0 and kept it on track for a gold medal showdown on Thursday against Taiwan, which also improved to 4-0 with a 15-0 rout of Philippines.

Second baseman Chen Yung-chi hit a three-run homer in the first inning when Taiwan scored seven times. The game was stopped after five innings under the tournament mercy rule.

There was equally lopsided results in women's field hockey, where four-time champion South Korea thrashed Hong Kong 15-0 and medal-contender Japan fired in 12 goals without reply against Taiwan.