BIRMINGHAM (AFP) - Li Xuerui, the Olympic and the defending All-England champion, suffered a stunning defeat on Wednesday when she lost in the first round of the All-England Open.

Li, widely regarded as the sport's outstanding woman player after her triumph at the London Games seven months ago, went down 21-18, 21-18 to Bae Yeon Ju, the world No. 13 from South Korea.

The Chinese player did not blame either the wind drift or having to face such a high quality opponent in the first round for her defeat.

"It was personal performance issues, too many mistakes, nothing else," she said.

Li's defeat opens up a better chance of her Chinese compatriot Wang Yihan, the number three seed and former All-England champion, reaching the final again in the top half.

Later two other Chinese seeds were beaten in the first round, both in the men's singles.

The most surprising was the defeat of the third-seeded Du Pengyu, the runner-up in the World Super Series finals, who went down 21-17,15-21, 21-18 to Chou Tien-chen, the world No. 28 from Chinese Taipei, who scored the finest victory of his career.

Earlier Hu Yun, the sixth seed, also failed to survive a long match, leading 19-17 in the final game and still losing 21-16, 11-21, 23-21 to Tanongsak Saensomboonsak, a qualifier from Thailand.