The 31-year-old won his first title at the 2003 Russian Open, but admitted that frustration at a lack of further tournament victories had caused him to question his future in the game.
However, at Pinx Golf Club Fraser's final-round three-under-par 69 secured that elusive second triumph at the weather-affected 54 hole event.
"I have had a lot of chances over the last six or seven years to win and I haven't taken them. A lot of doubt creeps into your mind and you start to question whether you deserve to be playing," said Fraser.
Northern Ireland's Gareth Maybin, who had shared the lead with Fraser after nine holes, faded down the stretch and finished tied for second with Australia's Brett Rumford.
Three-time major winner Ernie Els had moved ominously within a shot of Fraser and Maybin at the turn with three birdies, but played his back nine in five-over-par including a double-bogey.
Scotland's Stephen Gallacher closed with a 70 to finish on 214, two-under, and picked up 23,263 - his biggest cheque of the season.
That wasn't enough to secure the amount he required to hang on to his card at the end of a medical exemption but, having made the cut in his last seven events, the former Dunhill Links champion will be confident he can win enough money between now and the end of the season through the spot he secured at last season's Tour School.
David Drysdale, the only other Scot to survive the cut in South Korea, signed off with a 77 to finish on 217.