Wang Hao believes "he is a better player technically and mentally" as the defending champion edged out South Korean Ryu Seung Min to reach the quarterfinals through a hard fought seven-game match at the World Table Tennis Championships on Thursday.

The duel between the two top paddlers are always eye-catching since Ryu stunned Wang to lift the Olympics champion at the 2004 Athens Games. But since the painful defeat, Wang has overwhelmed Ryu with just one defeat.

"I have prepared for a tough game with my rival, but I believe I'm a better player no matter technically or mentally," said Wang.

"Even though, I knew I would have been in trouble if I couldn't keep my mentality fit when I face such a player."

Wang didn't started the match well as he lost the opening game 10-12 to Ryu. "I fought from 9-6 down to 10-6 but missed a high ball. I was kind of struggled for my momentum but then managed to pull myself together."

Wang took over 2-1 after winning the following two games 11-6, 11-8 but Ryu was tough enough to regain the lead 3-2. At the key moment, Ryu's coach was sent off for illegal advice and Wang nailed a sensational victory by winning the last two games.

Ryu showed no sign of frustration after the defeat and applauded Wang for his tough mind.

"Every time I play against Wang I am extra motivated and excited," Ryu said. "Because a lot of people expect to watch us play against each other. Today I had the opportunity to win. At the start Wang looked a bit nervous. When I was leading 3-2 I thought his mood was low, but mentally he is very strong."

Ryu refused to admit that the send-off of his coach affected his performance but Wang thought it might be a turning point for the intense contest.

"On these stages, any small factor could affect the final result," Wang said. "He might be affected and I played an upperhand."

Wang overcame his compatriot Wang Liqin in the final two years ago to win his maiden single title at the World Championships and this time he is more confident.

"I think Ryu could earn eight out of ten points for his play today, but I will only give myself seven points, I'm still away from my best."

Wang will fight for a semifinal spot against Japanese rising star Jun Mizutani.