Olympic champion Park Tae-Hwan of South Korea stormed to victory in the men’s 400 metres freestyle yesterday to retain his Asian Games crown.

Park, swimming in lane two, led from the start and never looked troubled, clocking 3:41.53 to finish ahead of Chinese pair Sun Yang (3:42.47) and Zhang Lin (3:49.15).

It was the South Korean’s second gold of the games after his win in the 200m freestyle.

Zhang, whom Park beat to the 400m freestyle gold at the 2008 Olympics in Beijing, will be bitterly disappointed with his swim, although he had complained of feeling tired ahead of the race.

Dubbed “Marine Boy” in South Korea, Park won three gold, a silver and three bronze medals in Doha four years ago.

His medal haul was the largest by a single athlete and he was named the most valuable player of the 2006 Games.

Defending men’s 50m butterfly champion Zhou Jiawei of China made it an Asian Games double yesterday, winning the gold to add to his victory over 100m.

The Asian record holder touched in 23.66sec, well clear of second-placed Masayuki Kishida of Japan, who clocked 24.13.

China then underlined their dominance with comfortable wins over main rival Japan in both the men’s 4x100m and women’s 4x200m freestyle relays. The Chinese men’s team edged the Japanese quartet by less than half a second, while the women took their final by more than four seconds.

Yesterday morning at the Aoti Aquatics Centre, Cambodian swimmer Hem Thon Vitiny was completely out of depth in her women’s 50m freestyle heat, finishing behind all seven other competitors with a time of 33.01 seconds.

The 18-year-old Phnom Penh native, who crashed out of the 50m breaststroke despite beating her personal best on Saturday, found the going real tough against classy opposition which included heat winner Tang Yi of China.

Vitiny was nearly seven seconds slower than the required time to make the cut for the finals, and managed to place faster than just one other swimmer, Siriphone Veomany of Laos. In the evening finals yesterday, Tang Yi was pipped by compatriate Li Zhe Si, who took gold with a time of 24.97.