World number two Wang Shixian crashed out to Juliane Schenk in the women's singles quarter-finals at the Japan Open on Friday as her top seeded compatriot Wang Yihan battled her way into the semis. The Asian Games gold medallist let a narrow lead slip in the second game to eventually go down 15-21, 19-21 to the eighth-seeded German. "I didn't play bad, but Juliane played patiently, she was calm mentally throughout the match today. I couldn't hit the shuttle the way I want to," she said. Schenk, who was full of praise for the full house at the Tokyo Metropolitan Gymnasium, said she enjoyed the challenge of playing top Chinese stars. "I've been playing many, many players from China right now and I already have some big wins against them. Of course, normally they are dominant," said Schenk. "I'm taking the challenge seriously. I just enjoy playing each time I come on court. It's just fantastic to play the best players," added the German, who will play Indian star Saina Nehwal in the semi-finals. World champion and top seed Wang Yihan dropped a game before rallying to beat 2007 Japan Open champion Tine Baun of Denmark 21-17, 14-21, 21-15. She will play fellow Chinese Liu Xin in the semis on Saturday, after her opponent eliminated Tai Tzu-ying of Taiwan 22-20, 21-15. Earlier, Nehwal, the 21-year-old former world junior champion, defeated Gu Juan of Singapore 21-17, 21-13. "She (Gu) is a good rally player and she has got good strokes. I knew that she plays quite slowly, she is not very fast, so I wanted to play fast," said Nehwal, fourth seed. In the men's singles action, Chinese world champion Lin Dan avenged his loss at the China Masters last week by beating teammate Chen Jin 20-22, 21-14, 22-20, overcoming a 13-18 deficit in the final game. "It was a difficult match, but I managed to win in the end. It's always difficult to play against my teammates," said Lin, who will play another teammate Chen Long, the winner over Jan O Jorgensen of Denmark 21-14, 21-13. Chen said: "Both played our best. A win or loss just depends on luck." Defending champion Lee Chong Wei of Malaysia fended off a spirited challenge from Japan's Kenichi Tago 21-23, 21-7, 21-18 and set up a semi-final meeting against two-time Tokyo champion Peter Gade of Denmark. Gade eased aside Simon Santoso of Indonesia 21-14, 21-15. Lee, who crashed to his arch-rival Lin Dan in the final at the world championships last month, said he has not recovered mentally from the shock defeat. "I had match points at 20-19 and 21-20. I had a chance to win but I lost the match. I'm in very low spirits since then," said Lee. "I just decided to come, because this is the 30th anniversary of the Japan Open."