YOKOHAMA (AFP) - China completed a clean sweep of all five titles at the World Table Tennis Championships Tuesday, with world number ones Wang Hao and Zhang Yining claiming the men's and women's singles events. The Chinese team dominated the event - held every two years - for the third straight time, with all-Chinese finals in each discipline. China also notched a clean sweep at the Beijing Olympics. Wang Hao, who won the men's doubles title with Chen Qi on Monday, made it a double victory with a 11-9, 13-11, 11-5, 11-9 win over three-time world champion Wang Liqin in the singles final. Zhang, the Beijing Olympic gold medallist and the favourite here, stormed back from two games down for a 10-12, 3-11, 11-2, 11-7, 11-7, 11-9 victory over world number two Guo Yue. Guo and Li Xiaoxia took the women's doubles title, while Li Ping and Cao Zhen clinched the mixed doubles title. Wang Hao, who won silver in Beijing, said his mental toughness had made the difference here in Yokohama. "I was very disappointed in the past championships and the two Olympic Games. But this time I prepared very well, since the Beijing Games. This is the result of that," said the 25-year-old champion. "Of course, it's important to practice, but I learned that it's also important to prepare well mentally. I'm in pretty good form since 2007 and I won the World Cup as well. I'm very confident right now."I'm very happy to become the singles world champion. My next goal, or dream, is to win the gold medal at the London Olympics in 2012," added Wang Hao, who improved his record against rival Wang Liqin to 10-11.Wang Liqin said: "I hadn't expected that I would finish runner-up, so I'm quite happy with the result." On the women's side, Zhang - who lost to Guo in the 2007 championships - stretched her head-to-head record against Guo to 10 wins and four defeats. "When I won the Athens Olympic singles and doubles gold medals, I was more excited. I'm not so excited this time, but still I'm happy about it," said Zhang, 27. "This is the first big tournament since the ITTF changed the rules and I didn't know how far I could reach with the speed of the ball reduced. I just tried to play my usual game and it was a big success to win the title. "Guo Yue is young and she has good skills as well. She is a tough opponent to play against. When I was 3-6 down in the last game, I just tried to do my 100 percent until the end." Meanwhile, Guo said: "I did my best. But sometimes I rushed too much. I tried to attack too quickly. She started to attack me in the third game and I was a bit late to cope with her attacks."