Vietnam's Nguyen Tien Minh took a step closer to his first victory of 2012 after coming from a set down to beat Malaysia's Daren Liew in the quarter-finals of the Singapore Open on Friday.
The unseeded Liew had eliminated second seed Lee Hyun-Il of South Korea on Thursday in the second round of the Super Series tournament.
He appeared to be on course for another surprise win at the Singapore Indoor Stadium when he took the opening game against sixth-seeded Minh.
But the world number 11 recovered to take the last two games comfortably and win the match 14-21, 21-11, 21-13, setting up a semi-final clash against Thailand's Boonsak Ponsana.
The Thai also came from a set down to beat Dionysius Hayom Rumbaka of Indonesia 21-23, 21-7, 21-18.
Minh is the highest remaining seed in the men's singles draw in the competition.
Top seed Sho Sasaki of Japan was eliminated by Viktor Axelsen of Denmark in the first round while third seed Kenichi Tago of Japan fell to China's Wang Zhengming in the second round.
Axelsen and Wang will meet in the other men's singles semi-final on Saturday after the Dane overcame Indonesia's Sony Dwi Kuncoro 21-17, 26-24 and Wang downed Chong Wei Feng of Malaysia 21-12, 22-20.
In the women's singles semi-finals, second seed Juliane Schenk of Germany will take on third-seeded South Korean Sung Ji-Hyun after both players came through tense three-set games.
Schenk overcame Thailand's Porntip Buranaprasertsuk 21-12, 9-21, 21-19 while Sung beat Japan's Eriko Hirose 21-14, 10-21, 21-13.
Fourth seed Cheng Shao-chieh of Taiwan beat seventh seed Sayaka Sato of Japan 21-15, 21-8 to set up a semi-final meeting with local favourite Xing Aiying, who got past Hong Kong's Yip Pui Yin 21-9, 23-21.