ZAGREB, May 24 (Xinhua) -- Table tennis colossus China fielded seven players each to the men's and women's singles competition. Four days and three rounds into the world championships, China has reported no casualty.

Wang Liqin, Hao Shuai, Chen Qi and Hou Yingchao triumphed Thursday night, joining Ma Lin, Wang Hao and Ma Long in the last 16.

Defending champion and second seed Wang Liqin gave a 11-7, 11-5,11-3, 11-9 beating to Argentina's Liu Song, who plays a chop-and-attack game.

Hou Yingchao, also a defender-cum-attacker, shook off a first set embarrassment in which he had trailed 0-9, as he beat Sweden's Fredrik Hakansson 2-11, 13-11, 11-5, 11-9, 11-6.

Hou was upset over a reporter's question on his first set trailing, saying: "Even if I was three sets down, I would have come back to win the match."

Hao Shuai had been humiliated too, in the third set of his 11-9,15-13, 0-11, 11-8, 11-5 victory over South Korean penholder Lee Jung Woo.

Chen Qi reached the fourth round after trouncing Chinese Taipei' s Chiang Peng-Lung 11-5, 11-6, 11-8, 11-8.

Ma Lin, four-time World Cup winner who has never won a singles world championship, blanked Spaniard He Zhi Wen 11-8, 15-13, 11-9,11-8 earlier in the day, while Ma Long whitewashed German Christian Suss 11-8, 11-5, 11-9, 11-5.

Suss' teammate Bastian Steger fell to Chinese Olympic silver medalist Wang Hao, 11-9, 11-6, 11-6, 11-6.

In the women's action, Chinese Yao Yan had the most difficult win as her more heralded teammate Zhang Yining had the easiest.

The 18-year-old Yao, who joined China's world championship team at the last minute, outlasted Hong Kong player Lin Ling 11-7, 5-11,6-11, 11-9, 7-11, 11-5, 16-14.

Tan Wen Ling of Italy, scheduled to face world No. 1 Zhang Yining Thursday night, pulled out of the world championships in the morning, citing a right shoulder injury.

Gennaro Bozza, a veteran reporter with the Italian newspaper LaGazzetta dello Sport and a friend of Tan, had a different explanation.

He said Tan was forced to quit the Zagreb championships after she challenged the authority of the Italian table tennis association.

"Tan was told last night in a team meeting that the Italian team no longer needed the service of a rebel and she should go home immediately," said Bozza.

Second-seeded Chinese Wang Nan and Chinese national champion Peng Luyang respectively beat Hong Kong players Zhang Rui and Jiang Huajun.

Chinese Guo Yue and Guo Yan, who are not related, beat Wu Jiaduo and Nicole Struse, both of Germany, in five sets.

Chinese Li Xiaoxia sent Svetlana Ganina packing.

China has booked three semifinal spots in the mixed doubles and two each in the men's and women's doubles.