CHANGZHOU, China -- Mixed doubles world No. 1 pair Zheng Siwei and Huang Yaqiong were unable to defend their title at the badminton China Open as the hosts fell to Seo Seung-jae and Chae Yu-jung of South Korea in the quarterfinals on Friday.

Zheng and Huang, the top seeds, took the first game 21-17. However, their fifth-seeded adversaries claimed the next two games, 21-13, 21-17. This marks another victory for Seo and Chae over Zheng and Huang, echoing their win at the World Championships final in Copenhagen just two weeks ago.

"I think they are more stable and faster than before. With two weeks to go before the Asian Games, we need to make adjustments and try our best to have good performance," Huang said.

Second-seeded Yuta Watanabe/Arisa Higashino of Japan and fourth-seeded Dechapol Puavaranukroh/Sapsiree Taerattanachai of Thailand also met their match at the quarterfinal stage.

In the women's singles, the top four seeds all advanced to the semifinals. World No. 1 An Se-young of South Korea bested Han Yue of China 15-21, 21-15, 21-17, while third-seeded Chen Yufei secured a 21-18, 21-11 victory over fellow Chinese He Bingjiao.

"I feel very honored that the Chinese players take me as a stronger opponent. In fact, I still have a lot to learn, and the Chinese players are like a mountain for me. I will continue to work hard," 21-year-old An commented.

Tai Tzu-ying of Chinese Taipei and Akane Yamaguchi of Japan also advanced to the women's singles semifinals.

In the men's singles, world No. 1 Viktor Axelsen of Denmark defeated Loh Kean Yew of Singapore 21-17, 23-21. Chinese competitors Shi Yuqi and Lu Guangzu both earned full-game wins and will face off in the semifinals.

In the women's doubles, top seeds and defending champions Chen Qingchen and Jia Yifan of China triumphed over Yuki Fukushima and Sayaka Hirota. They'll next challenge another Japanese duo Nami Matsuyama and Chiharu Shida, who overcame compatriots Mayu Matsumoto and Wakana Nagahara 21-14, 21-16.

In the men's doubles, China's Liang Weikeng and Wang Chang bested fellow nationals Liu Yuchen and Ou Xuanyi 21-18, 21-19, progressing to the semifinals.