World number one Lee Chong Wei turned on the style and even had time to attempt a trick shot as he sped into the Singapore Open semi-finals on Friday.

The Malaysian took just 29 minutes to demolish Thailand's Tanongsak Saensomboonsuk 21-8, 21-14 in breathtaking fashion, at one point even trying a shot from underneath his leg which fell short of the net.

It was exhibition stuff from Lee, who is the tournament's red-hot favourite after three of the top four seeds were late withdrawals, drastically weakening the men's singles field.

Tanongsak beat Japanese eighth seed Kento Momota in the first round but the gulf in class was clear during Friday's quarter-final against the confident and ruthless Lee.

On Saturday, Lee will meet India's K. Srikanth, who beat China's Hu Yun 17-21, 21-14, 21-19 -- after upsetting seventh seed Nguyen Tien Minh a round earlier -- for a place in the semi-finals.

In the other men's semi, Indonesian qualifier Simon Santoso will face Chinese fifth seed Du Pengyu for a place in the final.

Women's top seed and Olympic champion Li Xuerui went past Taiwan's Tzu Ying-tai in straight games, in a far more convincing display than her three-game struggle against Japan's Minatsu Mitani in round two.

Li won 21-10, 21-13 in 27 minutes to stay on course for a repeat of last year's final with defending champion and fellow Chinese Wang Yihan, who downed India's eighth seed P.V. Sindhu 21-19, 21-15.

Defending mixed doubles champions Tontowi Ahmad and Liliyana Natsir of Indonesia took just over half an hour to brush off Anders Kristiansen and Julie Houmann 21-8, 21-17 on their way to Saturday's semi-finals.

In the women's doubles, top seeds Christinna Pedersen and Kamilla Rytter Juhl downed Reika Kakiiwa and Miyuki Maeda 21-15, 21-5 to set up a clash with Japan's Misaki Matsutomo and Ayaka Takahashi.