Kellogg and Clark are the English national mixed doubles champions

Britain's mixed doubles pairing of Anthony Clark and Donna Kellogg boosted their Olympic hopes with a hard-earned victory over China's top pairing.

The European champions won 21-12 21-18 for their first win over world number two pair Zheng Bo and Gao Ling, in the Singapore Open quarter-finals.

Clark and Kellogg will play Denmark's unseeded duo Rasmus Bonde and Helle Nielsen in Saturday's semi-final.

Andrew Smith also reached the last four in the men's singles.

The world number 29 beat Malaysia's Kuan Beng Hong 21-15 18-21 21-15 to reach his first Super Series semi-final.

Gail Emms and Kellogg were knocked out at the quarter-final stage of the women's doubles by Indonesian pair Vita Marissa and Liliyana Natsir 21-17 18-21 21-17.