Zhang kept her composure in both games. In the first Chen overtook her from 9-13 down with a six-point streak; in the second the Chinese levelled from a 11-16 deficit and had four game points, only for Zhang to deny her the opportunity. The USA player closed it out in straight games, 21-17 24-22, to record her first win over Chen in five matches.
In the quarterfinals Zhang takes on Chen’s compatriot and 2016 champion He Bing Jiao, who won an all-China encounter over Wang Zhi Yi.
In men’s singles, defending champion Kenta Nishimoto was shown the door by Kunlavut Vitidsarn, with the Japanese unable to find a way past the steady defence of the Thai. Apart from a brief phase in the opening game when Nishimoto led 13-9, Vitidsarn was dominant throughout the match.
Japan had earlier suffered another blow, with Kanta Tsuneyama falling in straight games to Lakshya Sen. The hosts were left with Kodai Naraoka and Koki Watanabe in the men’s singles draw; Naraoka having had an early day after opponent Anders Antonsen retired in the first game.
Japan had reason to cheer in men’s doubles with Akira Koga/Taichi Saito outplaying Thailand Open champions Liang Wei Keng/Wang Chang 21-16 23-21. Their compatriots Takuro Hoki/Yugo Kobayashi repeated that feat against another Chinese pair, Ren Xiang Yu/Tan Qiang, 21-11 23-21.