HUANGSHAN, Sept. 10 -- Having had a two-week rest after FINA World Swimming Championships in Kazan, Olympic and world champion Sun Yang clocked an impressive time to win the 400m freestyle on the last day of the Chinese National Championships here on Thursday.

Sun, who swam 3:42.58 to retain his 400m world title in Kazan, was in his own class by storming in 3:42.70, good enough to win the world title since second-placed Jame Guy of Britain finished in 3:43.75 then.

"It's like a highly competitive training session for me. I am tired but happy with the result. After the national meet, I will go home to rest for some days," Sun said.

Sun has swept gold medals in the 200, 400 and 1,500m freestyle

Zhu Menghui took the women's 50m freestyle in 25.20 seconds, beating Liu Xiang of Guangdong (25.30) and Guo Tingru of Beijing (25.58).

Yu Hexin of Guangdong snatched the men's 50m freestyle in 22.66; Li Xuanxu of Hunan took the women 400m individual medley in 4:44.78; Huang Chaosheng added a gold for Hunan from the men's 200m breaststroke (2:12.60); Xu Danlu of Ningxia won the women's 800m freestyle in 8:35.83.

Beijing claimed the women' 4X100m medley relay in 4:04.71 while Zhejiang sealed the men's 4X100m medley relay in 3:36.79.

The five-day championships attracted 473 swimmers from 27 teams to participate in 38 events.