Number one seed Lee Hyun-il, a World Championship bronze medallist from 2006, battled into the last four by beating Hong Kong's Wei Nan 21-18, 21-13 at the Nimibutr Stadium.

He will meet Thailand's Tanongsak Saensomboonsuk, the last remaining hope for the home nation, in the semi-finals, after the 25-year-old knocked out another Hong Kong player, Ng Ka Long, 21-23, 21-11, 21-18. 

South Korea's second seed Son Wan-ho, meanwhile, knocked out his compatriot Jeon Hyeok-jin after coming from behind to prevail 11-21, 21-12, 21-11.

He will meet Hu Yun of Hong Kong for a place in the final, after he won another three game affair 23-21, 11-21, 21-11 against India's Sameer Verma.

In the women's draw, home fans will be dreaming of an all Thai final after both Ratchanok Intanon and Busanan Ongbumrungpan booked their semi-final spots.

Intanon, the number two seed, beat Nichaon Jindapon 21-14, 21-14 in an all Thai affair while teenager Ongbumrungpan brushed aside Indonesia's Dinar Dyah Ayustine 21-5, 21-18.

The prize for Intanon is a clash with South Korea's Sung Ji-hyun, who ended the hopes of another Thai player, Porntip Buranaprasertsuk, 21-17, 21-10.

Ongbumrungpan, meanwhile, will play China's Sun Yu who knocked out Hong Kong's Yip Pui Yin 21-15, 21-9.

The semi-finals are due to be played in Bangkok tomorrow.