Asian record holder Zhou Jiawei opened the gold account for China with a men's 50m butterfly title on the fourth day of swimming competition as the 23-year-old from Guangdong touched home first in 23.94 seconds, 0.08 outside his own Asian record set in the spring National Championships.

"I expected this victory because I had been focusing on this event," said Zhou who came fourth in the 100m fly on Sunday.

"But the result is not good enough for me as I aimed at breaking my own record in the race," he said.

Japanese national champion Ryo Takayasu took the silver in 24.11 and Chinese Wang Dong was third in 24.23.

Takashi Yamamoto, the 100m fly runner-up in the Athens Olympic Games, finished fourth in 24.26. He just became the first male swimmer to win the same individual event at three consecutive Asian Games after he defended his 100m fly crown on Sunday.

Defending champion Xu Yanwei sailed to the victory of the women's 50m freestyle, winning in 25.23.

Xu, five-gold winner in the Busan Asian Games four years ago, also entered for five events this time.

She had swam the fastest 50m split in the 4x100m free relay on Sunday when China took the gold and had a silver in the 100m butterfly on Saturday. She will compete in the 100m free and 50 fly events.

Pang Jiaying, 200 free champion on Saturday, came second in 25.84 to give China a one-two finish while Kaori Yamada from Japan was third in 26.01.

In the women's 4x200m free relay, defending champions China met no stiff competition as they clocked 8:01.89 seconds to win for the third time after the event was added to the Asiad program in 1998 Asian Games.

Pang anchored the Chinese team to reach the finish line first with three body-lengths of advantage after her Athens Olympic Games teammate Yang Yu was the second to swim.

Japan took the silver with 4.87 off the pace while South Korea were third in 8:14.68.

China bagged a silver in the 2004 Athens Olympic Games but then participants Zhu Yingwen and Xu Yanwei were missing from the roster this time.

In the last event, Japanese anchor swimmer Daisuke Hosokawa overtook Chinese Qu Jingyu in the final meters to bring Japan the win in 3:18.95, beating the previous Asian best by 0.25, set by themselves in last year's World Championships in Montreal. It has been the sixth time that Japan triumphed in the event at the Asian Games.

Defending champions China were pushed to the second in 3:19.26 before South Korea in 3:22.16.

Asami Kitagawa and Junichi Miyashita gave Japan two gold medals in the women's 100m breaststroke and the men's 100m backstroke respectively.

Kitagawa snapped China's winning streak in the event in three Asian Games as she scraped to triumph in 1:09.13.

The 19-year-old Kitagawa took a silver in the 50m on Saturday behind Chinese teenager Ji Liping, 18, who was second this time in1:09.47.

Ji missed the chance to make an Asian sweep in 50m and 100m breaststrokes as she already has the Asian Championships titles inboth events to her name this year.

South Korean Back Su Yeon settled for the bronze in 1:10.22.

Miyashita clocked a time of 54.67 to beat Chinese Ouyang Kunpeng, the silver medalist in 200m back here on Monday by one quarter of a second.

The 24-year-old Ouyang fell to Japan's Ryosuke Irie, 16, in the200m race.

Bronze went to another Japanese Masafumi Yamaguchi in 55.78.

Park, 17, pulled away from the leading pack including Chinese Zhang Lin and Japanese Takeshi Matsuda after the 350m mark before reaching for the title in 3:48.44 seconds in the men's 400m free.

Park, holding the Asian record in the event in 3:45.72, beat Zhang in their second meeting at the Asian Games as Zhang came second in 3:49.03.

Park overcame Zhang in the 200m free in an Asian record time on Sunday here before he defeated the 19-year-old in the 400m free for the gold.

Takeshi Matsuda, runner-up in the 200m butterfly here, came third in 3:49.38.

In the swimming medals table, China stand atop with 12 golds, 14 silvers and five bronzes and Japan rank second with 10 golds, 11 silvers and 11 bronzes. South Korea are third with two golds, one silver and seven bronzes.