Australian Matthew Griffin scored the biggest win of his career on Sunday with a one-stroke victory at the OneAsia Tour event in South Korea.

The 29-year-old from Melbourne led by two strokes heading into the final round and held his nerve with an even-par 72 to take him to nine-under for the tournament.

Griffin beat home South Koreans Kang Kyung-nam (68) and Park Sang-Hyun (71) to collect the $US178,000 ($A173,800) winner’s cheque at the hilly course in Gangwon-do province.

Kim Bi-o, winner of two events on the OneAsia circuit already this year, was a shot further back.

Australian Aaron Townsend (72) finished at six-under in a tie for sixth and compatriot David McKenzie was three shots further back.

“I am really, really thrilled,” said Griffin, who was once ranked the third-best amateur in the world.

“This is what I have worked for all my life, so it is absolutely amazing to finally get there.”

Griffin only scored his first four-round victory at the South Pacific Open in New Caledonia last year.

The win gives him a two-year exemption on the OneAsia Tour and puts him in good stead to tackle qualifying school on the US PGA Tour at the end of the year.