Champion Lin Dan of China battled into the semi-finals of the All England men's singles badminton championship in Birmingham, on Friday.

The 21-year-old top seed dropped a game before edging past South Korean Lee Hyun-il 15-10, 13-15, 15-8 in their quarter-final clash.

With the departure of second-seeded Dane Peter Gade in a third round match on Thursday and the withdrawal of injured Olympic champion Taufik Hidayat of Indonesia, Lin looks well set to retain his title -- a feat last achieved by Denmark's Poul-Erik Hoyer Larsen in 1996.

Lin's biggest danger looms from compatriot Chen Hong, the 2002 All England champion, who booked his semi-final with a 13-15, 15-12, 15-4 victory over countryman Bao Chunlai.

Home hopes of a title were kept alive by Olympic mixed doubles silver medallists Nathan Robertson and Gail Emms.

The British pair coasted past Indonesians Anggun Nugroho and Yunita Tetty 15-10, 15-3 to set up a semi-final with Zhang Jun and Gao Ling, the Chinese who won gold in Athens.