Lin Dan withdraws over waist injury

China's badminton superstar Lin Dan withdrew from his men's singles semi-final at the Asian Championships on Saturday, in a surprise move blamed on a recurring waist injury, state media said.

Organisers of the tournament said the top seed's injury recurred in morning training, forcing the four-time world champion, five-time All England winner and reigning Asian champion to pull out, according to the Xinhua news agency.

His withdrawal sends third seed Chen Jin straight to the final where he will face fifth seed Du Pengyu. The two Chinese players will battle it out in the eastern city of Qingdao on Sunday.

The Asian Championships are one of the last major tournaments before the upcoming London Olympics.

But the forfeit will not affect Lin's Olympic ambitions, as the 28-year-old has already qualified for the Games.

Meanwhile, China's promising women's singles player Chen Xiaojia, who had managed to cruise past the second and fifth seeds, was stopped in her tracks Saturday in her semi-final.

Chen was beaten 21-15, 22-20 by fourth seed Li Xuerui -- also from China.

Until now, the 24-year-old had been on a winning streak, beating fifth seed Saina Nehwal from India on Thursday, and then second seed Wang Xin on Friday.

Chen managed to level the score at 20-20 at the end of the second game with Li, but then lost on a service fault, Xinhua reported.

"Chen runs very fast in the court and it was very hard for me to defeat her, especially in the second set," Li was quoted as saying.

She will now face the winner of the other semi-final between third seed Wang Shixian and reigning world women's singles champion Wang Yihan.