Olympic and world champion Sun Yang claimed the men's 1500 meters freestyle title on the first day of the Chinese National Championships in Huangshan, east China on Sunday while Wang Lizhuo from Chinese Navy broke the men's 100m breaststroke national record and became the first Chinese swimmer to swim under one minute barrier.

Sun Yang celebrates after winning the men's 1500m freestyle final at the Chinese National Swimming Championships in Huangshan, east China Sept. 6, 2015. Sun claimed the title with 15 minutes 12.89 seconds. [Du Yu/Xinhua]

Sun, who was named MVP at the FINA World Swimming Championships in Kazan, August by winning two golds and one silver, clocked 15 minutes 12.89 seconds in his favorite 1500m freestyle.

"After I quit the 1500m freestyle at the last moment of the final in Kazan due to heart problem, I took two weeks off when I returned home. My coach did not suggest me to take part in this national meet according to my physical condition. But I just hope to show up to the fans who came from over the country. No matter how slow I swam, I just want to swim in the lane and say 'thank you' to my supporters," Sun said.

"For me, this meet is like a warm-up training regime for my next training program, and recovery session for my body," Sun said.

Wang Lizhuo stormed a new national record time 59.79 seconds to lift the title of men's 100m breaststroke, beating the previous national record 1:00.13 set by Li Xiang. Yan Zibei from Hubei came to second in 1:00.97 and Mao Feilian from Zhejiang third in 1:01.37.

"It was a pity that I did not qualify for the Kazan worlds. I hope I will not miss the Rio Olympic Games next year," said the 17-year-old Wang.

In other events, Zhu Menghui of Zhejiang made a big splash in women's 100m freestyle in 53.92; Liu Yaxin from Zhejiang bagged her first national champion by winning women's 200m backstroke in 2:10.02; Yang Zhixian from Hunan dominated the men's 200m individual medley in 2:00.67; Suo Ran of Chinese Navy topped the women's 50m breaststroke 31.69; Wang Siqi of Beijing clocked 2:08.49 in women's 200m butterfly; Zhejiang won the men's 4X200m freestyle relay in 7:20.70.

There were 473 swimmers from 27 teams to compete in the five-day national meet.