CHONGQING, China, Sept. 23 (Xinhua) -- Ouyang Quenpeng clinched the title of the men's 100 meters backstroke here on Sunday at the national swimming championships, but still needed to fight for meeting the Olympic A qualification standard.

The Chinese top backstroker finished the final first at 55.66 seconds, followed by Zhao Tao from Chinese Navy and Shanghai's SunXiaolei at 56.49 and 56.95 seconds respectively.

The top three swimmers all met the Olympic B qualification standard of 57.07 seconds, but failed to reach the A standard of 55.14 seconds.

"I got no pressure at all. I'm here just for easing up myself," said the former Asian record holder Ouyang. The 25-year-old revealed that he has been readjusting his techniques since this year and aimed to meet the A qualification standard next year.

According to rules of FINA, an NOC may enter a maximum of two qualified athletes in each individual event if both entered athletes meet the A qualification standard for the respective event, or one athlete per event if they have met the B qualification standard only.

There is no Chinese athlete that has swam under the A qualification standard in the men's backstroke events.

In the women's 400 meters individual medley final, Hunan native Li Xuanxu representing team Guangzhou took the victory at four minutes and 43.18 seconds.

The 13-year-old unheraldedly won the titles of 200 and 400 meters individual medley at the national championships this May, swimming under the A qualification standard in both events.

As all-rounder Qi Hui missed all the competitions after being frustrated at this year's FINA World Championships in Australia, Li surprisingly held the top positions in the individual medley events in China.

Besides, national team member Chen Yanyan touched the wall first in the women's 100 meters backstroke final. Her result of one minute and 1.45 seconds is 0.25 second faster than the OlympicA qualification standard.

Lai Zhongjian of Chinese Navywon the men's 100 meters breaststroke at one minute and 2.70 seconds. Zhang Enjian from team Wuhan took out the gold of men's 200 meters freestyle in one minute and 49.05 seconds.