The German recovered from being two games down but the unfancied 22-year-old Chinese player dug deep to secure an 11-6, 12-10. 8-11, 11-6, 5-11, 11-9 victory.

He will face Quadri Aruna in tomorrow's semi-finals after the Nigerian edged a thriller 4-3 against Jun Mizutani of Japan.

In a topsy-turvy encounter Aruna progressed 8-11, 11-9, 6-11, 12-10, 11-9, 4-11, 13-11.

Harimoto Tomokazu won an all-Japanese last eight battle 11-7, 11-6, 14-12, 7-11, 13-11 against compatriot Takuya Jin

Marcos Freitas of Portgual awaits in the last four after defeating Chih-Yuan Chuang of Chinese Taipei 3-11, 11-2, 11-3, 11-13, 4-11, 11-5, 11-9.

Women's top seed Kasumi Ishikawa of Japan was knocked out in straight sets as China secured three of the four semi-final berths.

Ishikawa lost 10-12, 5-11, 9-11, 4-11 to He Zhoulia in just under 39 minutes.

Compatriot Mima Ito progressed to the women's singles quarter-finals against Singaporean Yu Mengyu by virtue of an 11-5, 11-8, 6-11, 11-6, 11-8 scoreline.

She will face Chen Xingtong of China in the last four after she won 11-6, 11-8, 11-2, 11-4 against Jeon Ji-hee of South Korea.

Xingtong's compatriot Wu Yang progressed to the semi-finals after Hitomi Sato of Japan withdrew from their quarter-final clash.

Japanese duo Jun Mizutani and Ito won gold in the mixed doubles final.

They defeated Ma Te and Wu Yang of China 11-8, 12-10, 9-11, 11-9.