HANGZHOU, China, Sept 27, 2023 (BSS/AFP) - World champion Zhang Yufei roared into the Asian Games 100m butterfly final with the year's third-fastest time Wednesday, but Japan's double Olympic gold medallist Yui Ohashi opted out of the 400m medley.

China's Zhang, who has already claimed the 200m fly title in Hangzhou to go with her Olympic gold, surged to the wall in a Games-record 56.20sec.

Japan's Ai Soma (57.92) and China's Wang Yichun (58.09) also went through.

Rikako Ikee, the standout performer at the last Asian Games, where she won six golds, qualified in seventh.

The Japanese star, who was diagnosed with leukaemia in 2019, skipped the 100m freestyle on Tuesday with a cold.

Zhang now owns five of the top 10 best times this year with her new mark just shy of her own world-leading 56.12, bolstering her case as hot favourite at the 2024 Paris Olympics.

A 100m butterfly silver medallist at the Tokyo Olympics, behind Maggie Mac Neil, Zhang turned the tables at the world championships in July by edging the Canadian to win gold.

Ohashi, who won the 200-400m medley double in Tokyo, was a no-show to defend her 400m Asiad title.

The 27-year-old finished just sixth in the 200m medley on Monday with Japanese reports saying she was struggling with motivation.

She also skipped the 400 at the world championships.

In Ohashi's absence, China's Yu Yiting (4:44.25) took charge on Wednesday ahead of Japanese pair Ageha Tanigawa and Mio Narita.

The men's 200m freestyle final is shaping as a battle between South Korea's world bronze medallist Hwang Sun-woo and fast-improving Chinese teenager Pan Zhanle, who swam a sensational 46.97 to take the 100m gold in Hangzhou earlier this week.

It made him only the fifth man ever to go under 47 seconds.

Hwang qualified fastest in 1:47.08 with a cruising Pan fourth in 1:48.42.

In other races, Japan's Katsuhiro Matsumoto was fastest through the men's 100m butterfly heats in 51.88, while China's Wang Xueer (1:00.87) topped the timesheets in the women's 100m backstroke.

Japan's Satomi Suzuki (1:06.49) led the pack into the final of the women's 100m breaststroke.

China have been relentless so far in the pool, winning 15 of 20 golds over the first three days.