DOHA, Dec. 6 (Xinhua) -- Three Chinese teams remain unbeatable and one lost in Wednesday's beach volleyball action at the Asian Games.

    Top seeds Wu Penggen and Xu Linyin beat Ardiyansah Andy and Darkuncoro Koko Prasetyo of Indonesia in a close score of 21-19, 21-19.

    "We are not familiar with our opponents and they are good at defense and also moved very quickly. That's why we lost so many points," said Wu.

    Wu and Xu will clash with teammates Zhou Shun and Li Jian in next round.

    For fourth-seeded Zhou and Li, the victory came even harder as the two players spent more than one hour and came from one set down to steal victory from Kazakhstan's Vorobyev Dmitriy and Sidorenko Alexey.

    "We didn't play well today, but it didn't matter as the games are not over yet," said Li Jian. "We will have to put in a lot of effort in the next match against our teammates as they rank higher than us in the world. Anyway, we will fight to win."

    In the women's games, top-seeded Chinese Wang Jie and Tian Jia, rated second in the world, was in a class of their own, making it to the semifinals with a 21-11, 21-16 win over Thailand's Kulna Kamoltip and Sannok Jarunee.

    However, their compatriots and second seeds Xue Chen and Zhang Xi lost 20-22, 21-15, 17-19 to Japan's third seeds Tanaka Shinako and Koizumi Eiko.

    In another two matches of the day, two Japanese men's teams meta different fate.

    Third seeds Nishimura Koichi and Watanabe Satoshi staged a comeback 2-1 victory over a Kazakhstan team, while second seeded Asahi Kentaro and Shiratori Katsuhiro were defeated by Indonesian duo Salim Agus and Supriadi Supriadi 25-23, 21-17.