China's defending champions made successful performances in both women and men's 100m freestyle as well as the 200m breaststroke.

Chen Zuo powered to defend the men's 100m free in an Asian record time after he had to settle with two silver medals in 4x100m and 4x200m free relay while Japan claimed golds in both events.

He led the field all the way and powered to the finish in an Asian record time of 49.06 seconds, beating his own Asian mark by half a second.

"To tell the truth, I had expected to break the record before the race, so I am very happy with the result," said the 24-year-old Chen.

"In the relay event yesterday, although my team only had a silver, my personal result was not bad which gave me a lot of confidence today," he said.

In Tuesday's 4x100m free relay, Chen clocked 48.73, faster than his Chinese teammates and any other swimmer in this event.

South Korea's golden boy Park Tae Hwan was pushed to the second in 55.02 after taking the 200m and 400m free titles. Daisuke Hosokawa, anchor of the 4x100m winning team of Japan, was third in50.25.

Xu Yanwei won the women's 100m free to claim her third gold medal here as the five-time champion in Busan Games four years ago pulled off the win in 55.02, beating her Chinese compatriot Pang Jiaying to the second place in 55.17. Kaori Yamada of Japan was third, 1.27 off the pace.

Xu clinched the sprint double after she took the 50m free Tuesday after the 4x100m free relay triumph.

Pang missed her fifth win here after she grabbed the 200m free gold from her Athens Olympic Games teammate Yang Yu Saturday when she was crowned in 4x100m medley relay. She also won the 4x100m and 4x200m free relay on Sunday and Tuesday respectively.

In women's 200m breaststroke, former world record holder Qi Hui stormed to the finish in 2:23.93 as the Athens Olympic Games sixth-place finisher took her second title in her favorite event. Qi claimed the 400m individual medley on Sunday.

Luo Nan of China bagged the silver in 2:27.49 after she rallied her teammates to win the 4x100m medley relay here. Jung Seul Ki of South Korea, 18, was third with 3.89 adrift of the pace.

Japanese Hidemasa Sano overcame compatriot and Asian record holder Ken Takakuwa for the men's 200m individual medley gold and Reiko Nakamura triumphed in women's 100m backstroke.

In the last event of the night, Yurie Yano beat China's 400m free champion Yang Jieqiao for the 800m free title.

Sano, finishing fifth in last year's world championships in Montreal, raced to the title in 2:00.73.

Takakuwa, holding the Asian record in 1:59.81, was second in 2:01.03 before Han Kyu Chul from South Korea in 2:02.56.

Nakamura, finishing fourth in both Athens Olympics and last year's world championships, breezed to the win in 1:00.82.

It is the second gold here after the 200m back bronze medalist in both Athens and the worlds took the 200m title on Sunday.

China's Xu Tianlongzi, 15, was second in 1:01.22 before teammate and 50m back Asian Games champion Zhao Jing in 1:01.72.

Yano won in 8:29.51, beating Yang by 8.84 while Maiko Fujino, also from Japan, took bronze in 8:42.31.