Bae Sang-moon fired a two-under-par 69 on Sunday to claim victory at the Kolon-Hana Bank Korea Open as Ian Poulter's challenge collapsed on the closing holes.
The Englishman held the lead as the Asian Tour event at Woo Jeong Hills Country Club entered its closing holes but bogeyed the 16th and 18th to hand the title to the 22-year-old Korean, who parred the final eight holes of his round to finish on 11-under-par 273.
American Anthony Kim carded an even-par 71 to finish in a tie for third on nine under with overnight leader Kim Wi-joong (72), while former winner Kim Dae-sub was alone in fifth a further shot back after a closing 72.
Korea's Lee in-woo fired a closing 65 to join compatriot Kim Hyung-tae (70) and Australia's Jason King (69) in a share for sixth spot.
"I'm extremely happy and I don't think I've realised the magnitude of my win. I'm very proud of myself," said Bae, who moved up to fifth on the Asian Tour's Order of Merit after his second career Tour win.
"The birdie on the 10th hole kept my momentum going for the rest of the day. That birdie gave me the confidence needed to keep it going in the closing holes."
Poulter, meanwhile, was less than pleased with his poor finish.
"I came here to win but I am going home second, so I'm not very happy," said the 32-year-old Englishman.
"But it's nice to come here with so many fans and I'm glad I could show them some good golf this week."