China secured places in the women's and mixed doubles finals at the BWF World Championships on Friday.

Two Chinese pairs in each category reached the last four and will encounter each other in the semis.

In the mixed doubles, three-time winners Zheng Siwei and Huang Yaqiong needed only 27 minutes to ease past South Korean duo Kim Won-ho and Jeong Na-eun 21-10, 21-6 to progress.

"Our tactics today were very clear, which was to make them move around. Last time, we didn't use the court space well. The opponents are very special in mixed doubles, they usually put the male player upfront, which is different from other mixed doubles pairs. We prepared for this aspect," said Zheng, who had lost to the South Korean pair in the Singapore Open earlier this year in their only previous meeting.

Next up for Zheng and Huang are compatriots and worlds debutants Jiang Zhenbang and Wei Yaxin, who dispatched Denmark's home favorites Mathias Christiansen and Alexandra Boje 21-16, 21-18 to advance.

The path to the semifinals for China's two women's doubles pairs was more tumultuous. Top seeds and three-time world champions Chen Qingchen and Jia Yifan came through a hard-fought battle to emerge victorious over Japan's Nami Matsuyama and Chiharu Shida 21-15, 16-21, 21-16.

"This was the best performance they've had against us. They played really well, and several times on the court we felt like we were going to lose, but we kept motivating each other, encouraging each other and managed to pull the match back," Chen said after their victory.

"Winning today's match was truly exhilarating. This is already our sixth World Championships, and we aren't sure how many more we'll have in the future. Unlike the first time when we felt we'd definitely have more opportunities to come, we really wanted to win this time," Chen added.

In the semifinals, Chen and Jia will face teammates Zhang Shuxian and Zheng Yu, who pulled off a major comeback against Malaysia's Pearly Tan and Thinaah Muralitharan. Zhang and Zheng bounced back from 12-6 in the second game after losing the first, unleashing their determination before eventually winning 17-21, 21-17, 21-19.

"In the second game, we told ourselves that we had no other choice but to push ourselves and give it our all," Zheng said. "In the decider, there wasn't much consideration of tactics. It was about being more resolute during crucial points, having a determined shot, a determined mentality, so we played better than before."

In the men's doubles quarterfinal, third-seeded pair Liang Weikeng and Wang Chang of China defeated Indonesia's Muhammad Shohibul Fikri and Bagas Maulana 21-18, 15-21, 21-14. China's other men's doubles duo of Liu Yuchen and Ou Xuanyi will take on Malaysia's Aaron Chia and Soh Wooi Yik later on Friday.