Japan's third seed Kasumi Ishikawa went out in the first round of the Japan Open on Friday, losing 4-1 to China's Wang Manyu in the women's singles.

Ishikawa, who lost in the quarterfinals at the world championships to top-ranked Ding Ning last month, this time came up short against Wang, who had beaten the Japanese in straight games when they first met in February at the Qatar Open.

Ishikawa won the first game 11-6 but her backhands began to falter in fast rallies in the face of an aggressive Wang and she missed a serve to hand the Chinese a 2-1 lead.

After going down 10-8 in the fourth game, Ishikawa came back to force a deuce with a forehand drive and twice seized game point but eventually fell 14-12, the moment she believes sealed her fate.

"If I could have pulled it back to 2-2 then the match would have been anyone's," Ishikawa said. "I won the first game but she adjusted her distance and slowed the game down."

"I couldn't return her serves at all last time, but I was returning well from the start. She's someone who has beaten Ding Ning, so I went into the game as a challenger. She was really good with her backhand."

Top seed Feng Tianwei of Singapore, ranked fourth in the world, lost 4-1 to Sun Yingsha of China in the second round in another shock.

Asian champ Miu Hirano, who won bronze at the worlds, powered her way past Suh Hyo Won, leaving the chop-minded South Korean out of gas in the closing stages of a straight-game mauling.

"She wasn't someone who comes out attacking so I headed into the match thinking it'd go down to the wire, to 4-3. It boosts my confidence to win 4-0," said Hirano, whose fortunes have turned since she adopted a more aggressive attacking stance.

"I think the attacking practice is paying off to some extent. I couldn't strike through (the opposing defense) but they sometimes go through now thanks to the power and pace I've acquired."

With the three Chinese atop the world chart all skipping the event at Tokyo Gymnasium, the 17-year-old national champ sees this as a golden opportunity.

"There are only a handful of top players here. Instead, there are many young ones. I've won against the top players so I ought to think I have a better chance of beating young players. I'm here to win it."

Eighth seed Mima Ito's patient display saw her past South Korea's Yang Ha Eun 4-2. She was tied three times by China's Chen Ke in the second round, but won in seven games.

"I had games where I led early but let my opponent back in, which is something I can't afford to do against high-ranked players," Ito said.

Seventh seed Hitomi Sato went out in the second round, her chopping defense was overcome by German Shan Xiaona in a 4-1 defeat.

Nine-time defending Japan men's champ Jun Mizutani suffered a shock 4-0 defeat to 13-year-old countryman Tomokazu Harimoto at the worlds last month, but took his first step forward in the men's singles with a solid 4-1 win over Germany's Bastian Steger.

"I have a sense of urgency with only two singles berths available for the 2020 Tokyo Olympics," Mizutani said. "It's getting difficult with many good young players coming through, but I want to compete at Tokyo so I need to get better."

Maharu Yoshimura pushed top-ranked Ma Long of China all the way in the first game but lost 18-16 en route to a straight-game defeat.

"He made fewer and fewer mistakes the tighter things got. He crushes what you want to do," Yoshimura said. "He also makes very few careless mistakes and has few weak points."

Ninth seed Koki Niwa let German Ruwen Filus come back after leading 3-0 but eventually went through with a 4-3 win, and beat countryman Jin Ueda 4-2 in the second round.

Kenta Matsudaira, seeded 10th, won in full games against Ricardo Walther but lost 4-1 to Chinese third seed Xu Xin.

In the men's doubles, Niwa and Yoshimura, part of the Rio silver-winning team and the bronze-winning pair at the recent worlds, defeated Ho Kwan Kit and Wong Chun Ting of Hong Kong 3-1 to set up an all-Japan semifinal against top-ranked compatriots Masataka Morizono and Yuya Oshima, who won the silver at the worlds.

In women's doubles, Honoka Hashimoto and Sato reached the last four after easing past Cheng Hsien-tzu and Lin Chia-chih of Taiwan in straight games.