A spectacular collapse by Japanese amateur Hideki Matsuyama saw him falter as he looked to secure qualification for the 2012 Open Championship at Royal Lytham.
The 20-year-old looked set for a top-four finish after going six under par for his first nine holes at the Amata Spring Country Club in Bangkok.
However, Matsuyama was left needing a par at the last after stumbling to a double bogey at 16 and a bogey at 17.
The amateur could only manage a triple-bogey seven at the last after being kept waiting for almost two hours following delays caused by lightning.
As a result, Singapore's Mardan Mamat won a three-man playoff after finishing in a tie for fourth with compatriot Chih-Bing Lam and American Jonathan Moore.
Anirban Lahiri from India, Prayad Marksaeng from Thailand and Kodai Ichihar of Japan made up the quartet of qualifiers.