Olympic champion Zhang Yufei stormed to win the women's 100m butterfly at China's National Swimming Championships here on Thursday.

Zhang, winner of the 200m fly and runner-up in the 100m fly at the Tokyo Olympic Games, timed 56.48 to grab the gold. Her time is the world's fastest time in the event so far this year. She also won the 200m fly in Hangzhou on Monday.

Yu Yiting ranked second in 57.51, while Wang Yichun came third in 57.85. Yu also took part in the 400m medley later in the day and snatched the gold in 4:35.61.

Pan Zhanle, who broke the men's 100m freestyle Asian record on Monday, came from behind to win the men's 200m freestyle in 1:44.65, also the world's fastest time in the event so far in 2023. Wang Shun came second in 1:45.71, having led early on before being overtaken by Pan after 100m.

"I didn't expect to surpass Wang and I was quite nervous in the competition," said Pan. "I hope I can achieve good result in the event in the Asian Games at home."

In the men's 100m fly, Wang Changhao touched first in 51.73, with Sun Jiajun and Chen Juner ranking second and third respectively.

Wang Xue'er entered 59 seconds in the women's 100m backstroke as she timed 58.99 to win the event. Wan Letian and Peng Xuwei were second and third respectively.

Also on Thursday, Yang Chang won the women's 100m breaststroke in 1:07.80, far behind the event's national record of 1:05.32. Guangdong won the mixed 4X100m medley relay title in 3:46.35.

The National Championships, running from May 1 to 6, also serves as a qualification for the Swimming World Championships in Fukuoka, Japan in July and the Hangzhou Asian Games in September.