China swept all the semifinal berths in the men's and women's singles events after winning a full set of mixed doubles medals at the world table tennis championships on Sunday.

Ma Lin defeated South Korea's Joo Se Hyuk and advances to the men's singles semifinals.

Yao Zhenxu, a vice chairman of the Chinese Table Tennis Association (CTTA), didn't jump to his feet in celebration. Rather, he was worried - about table tennis's future at the Olympic Games.

"If one team keeps winning all at the world championships and Olympics, table tennis' Olympic future is in danger," said Yao, who had also been the International Table Tennis Federation's technical chief since 1995.

China, which won all table tennis golds at the Beijing Olympics, saw the top four seeds - Wang Hao, Ma Lin, Ma Long and Wang Liqin – reach the men's singles semifinals.

The women's semifinal spots were snapped up by Zhang Yining, Guo Yue, Li Xiaoxia, the top three seeds, and 10th-ranked Liu Shiwen.

In the early afternoon, Li Ping and Cao Zhen combined to beat national team colleagues Zhang Jike and Mu Zi 11-6, 4-11, 11-7, 9-11, 13-11, 11-8 to clinch the mixed doubles gold.

Guo Yue advances to the women's singles semifinals after defeated Singapore's Feng Tianwei.