Scott Hend held off a stunning late charge from home favourite Piya Swangarunporn to win the True Thailand Classic presented by Chang.
The Australian came into the final round at Black Mountain Golf Club six shots ahead of Swanagarunporn but was a shot behind with five holes to play as the Thai fired a brilliant course record 63 to get to 17 under.
A birdie on the 14th put Hend back into a share of top spot and when he took advantage of the driveable 17th for the fourth time this week, that was enough to secure a 68 and a second European Tour title by a single shot.
Hend could move into the top 80 in the Official World Golf Ranking after his win, a long way ahead of the runner-up who came into the week 798th in the world and with a best career finish of third in Hua Hin on the Asian Tour in 2010.
Hend held the 54-hole lead at the inaugural staging of this event last year but a bogey on the 17th - which he has birdied the other seven times he has played it - ended his chances, and he was pleased to get some redemption.
This is a great win and I would love to try to kick on now and get another win, try to qualify for The Open - Scott Hend
"For Piya to shoot 63 today was an amazing round. He set the score and the target and then I had to just try to keep making birdies and try to catch him.
"I learned from last year when I pushed too hard on the 17th here and lost my chance to win. So this year I knew I had to be patient and let the golf course come to me.
"To win this tournament, after last year's disappointing finish and to get back into the winner's circle in Europe and to stay in the winner's circle in Asia, is extremely important to me and I'm very proud to win this title."
Belgium's Thomas Pieters fired a closing 68 to finish third on 15 under, a shot clear of American Peter Uihlein.
Hend entered the day with a two-shot lead but that was quickly wiped out when Pieters birdied the first and then holed a bunker shot on the second for an eagle.
The 2014 Hong Kong Open champion soon moved ahead with a birdie on the same hole and the lead was back up to two when Pieters made a three-putt bogey on the third.
Swangarunporn had birdies on the second, fourth, sixth and seventh to turn in 32 and move into contention, and when he holed his pitch into the tenth for an eagle he was just two behind Hend.
Back-to-back birdies on the 13th and 14th, the latter courtesy of a 40-foot putt, moved the 32 year old to the summit before he rolled a 20-footer up the hill on the 18th for another birdie and the lead on his own.
Hend then made a birdie putt from the fringe on the 14th to get back into a share of the lead before driving the green on the penultimate hole and getting down in two putts.
Swede Pelle Edberg finished at 13 under, a shot clear of Dutchman Joost Luiten and two ahead of Benjamin Hebert, Jeev Milkha Singh and Simon Yates.