Defending champion China beat Thailand with 4-1 to sit atop in Group A to the Sudirman Cup knockout stages on Wednesday evening.

Mix doubles Feng Yanzhe and Wei Yaxin beat Teeraratsakul Pakkapon and Muenwong Phataimas 23-21, 21-11. Facing Thailand's Wangcharoen Kantaphon in the men's singles, Li Shifeng beat him 21-18, 17-21 and 21-13 in an 85-minute thriller.

Women's single world No. 2 Wang Zhiyi endured a grueling battle with Intanon Ratchanok. Wang dropped the first set 19 to 21 and recovered to clinch the second 21-13. However, Wang lost the decider 21-23.

"She played very aggressively today. I didn't do well in many details, which gave my opponent lots of opportunities and confidence. I hope my failure can be transformed into valuable experience," said Wang.

In the men's doubles and women's doubles, China had comfortable wins, with Liang Weikeng and Wang Chang beat their opponents 21-14, 21-14, while Liu Shengshu and Tan Ning won 21-11, 21-8.

In Group B, four-time champion South Korea overcame another men's singles stumble to defeat Chinese Taipei 4-1, ranking first in the group.