A 40-foot putt from the back of the green on the 18th guaranteed him the third-round lead on Saturday and it turned out to be the winning shot at the OneAsia event at the Pinx Golf Club.
"It's unfortunate to finish like this, but I'll take it," Griffin, who leapt to the top of the OneAsia Order of Merit with the win, said.
"I thought my final putt yesterday was big as it gave me the lead, but I didn't think it would be the winning putt. It just goes to show you really must try and make everything."
South Korea has been a happy hunting ground for Griffin and it was in the same country that he won his last OneAsia title with victory in the Charity High1 Resort Open in September.
"High1 was fantastic but this feels even better," the 29-year-old from Melbourne said. "I never really played well in Korea in the past, which is surprising because I think the courses suit me but it looks like I've found my way here now."
South Korean veteran Kang Wook-soon had to settle for second place, a stroke behind on 12-under for a three round total of 204.
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