Top Chinese seeds Hao Shuai and Mu Zi had no troubles advancing to the second round of mixed double on Monday at the World Table Tennis Championships in Rotterdam, while number two seeds Zhang Chao and Cao Zhen just lost one game.

Hao Shuai and Mu Zi beat Yermek Beknazarov and Gulchekhra Khusseinova from Kazakhstan in straight games of 11-2, 11-2, 11-9, 11-1. Only in the third game Beknazarov and Khusseinova could keep up a bit with the Chinese pair. After they lost that game they thought they had lost the match, but the referee told them to continue for a fourth game.

Hao Shuai explained his feelings after the match. "I was pretty relaxed before the match," he said. "But I felt a bit nervous when I began playing. After all it's a world-class event."

In the next round, Hao and Mu will play against the Brazilians Cazuo Matsumoto and Ligia Silva, who beat Quadri Aruna and Ganiyat Olatunde from Nigeria after five thrilling games of 6-11, 11-7, 8- 11, 11-6, 11-6, 11-9.

Second seeded Zhang Chao and Cao Zhen defeated Marcos Madrid and Yadira Silva from Mexico 11-9, 6-11, 11-1, 12-10, 11-3. They will meet Austrians Stefan Fegerl and Li Qiangbing in the second round.

The third and fourth seeded Seiya Kishikawa and Ai Fukuhara from Japan and Cheung Yuk and Jiang Huajun from Hong Kong, China also qualified for the next phase of the tournament.

Kishikawa and Fukuhara beat Bojan Crepulja and Andrea Todorovic from Serbia 11-7, 11-3, 11-9, 11-9, while Cheung and Jiang were too strong for Michael Landers and Erica Wu from the United States with 11-7, 11-7, 11-4, 11-2.

Chinese duo Yan An and Feng Yalan (5/8) had some difficulties with Robert Floras and Antonina Szymanska, but also managed to continue. They needed six games to beat the Polish pair 9-11, 11-9, 11-8, 11-8, 9-11, 11-5.

Yan An admitted it was not their best performance. "We were nervous during the match because it's the first time that we compete at the World Championships," he declared. They will play Suraju Saka and Yang Fen from Congo in the second round on Tuesday.