Denmark's Thorbjorn Olesen held off a final-round challenge from world No. 22 Victor Dubuisson to claim the Perth International at Lake Karrinyup.
The 24-year old shot a one-under-par 71 on Sunday to finish at 17-under - three shots ahead of the Frenchman.
Olesen claimed the first prize of $291,660, which importantly thrust him well inside the top 60 for the Race to Dubai.
He handled the pressure better than his world ranking of 130 might suggest to card the lowest score for the tournament in its three years, beating Bo Van Pelt's 16-under in 2012.
But the day was not without its nervous moments for the overnight leader. After not dropping a shot on the front nine in his first three rounds, he bogeyed the par-four sixth hole on Sunday, after having started the final round with a three-shot lead.
He also dropped shots on the 10th and 12th holes to go to one-over for his round.
But the challenge from his nearest rival at the start of Sunday, Korean Sihwan Kim, was already seen to. Kim needed a top-two finish to retain his European Tour card for 2015, but that went out of the window on the 560-metre par-five seventh hole.
His third shot lipped out of a bunker, but his next three were played out of sand. He dropped three shots on the hole to go to 10-under par. He finished in a tie for ninth spot at 10-under with rounds of 66, 68, 69 and 75.
On that same hole, Olesen recovered from a wayward tee shot to record a birdie and go to 17-under.
Dubuisson saved his best golf for the final round, shooting a six-under-par 66 after rounds of 71, 67 and 70. He produced a bogey-free round, with birdies on the first and seventh holes on his front nine, and at four of the first six holes on the back nine.
He even managed to pick up a shot at the 135-metre par-three 12th hole - the shortest on the course - that had cost him four shots in the previous three rounds, including a double bogey on Saturday.
But Olesen proved up to the task and did not drop a shot over the final six holes, making birdies on the 13th and 15th holes and claiming his first tournament win since the Sicilian Open more than two years ago.
Englishman Mark Foster completed a trifecta for the Europeans, with a final round 69 to finish at 12-under.
Victorian Matthew Griffin carded an impressive final round of five under par 67 to finish at 11-under in a tie for fourth place and earning a $63,840 payday.
