Overnight leader Louis Oosthuizen eased to a one-shot victory in the ISPS HANDA Perth International after a final-round 71 at Lake Karrinyup Country Club.

The 33-year-old world No. 21 took a third-round three-shot lead into the final day before he finished on 16 under, one shot ahead of Frenchman Alexander Levy - with three birdies and a bogey either end of his round - to claim his eighth European Tour title.

The win sees the 2010 Open Championship winner move ahead of compatriot Branden Grace and back into fourth place for South African wins on the European Tour, making it six victories in 11 events for the Rainbow Nation this season.

Oosthuizen rued his poor start but was delighted to claim his first win since victory at the Volvo Golf Champions 2014.

He told Sky Sports 4: "I missed the greens on the second and third and was a little rattled after that but I settled in nicely and went back to just hitting greens and giving myself opportunities.

"I love Perth and the golf course. It's somewhere I would love to come back to. It's a great course to play.

"It's been two years since I had a win so this is massive for me going into the season. I'm flying tonight and playing Doral next week so hopefully I can take a lot out of this and play well."

Local favourite Jason Scrivener carded 69 to finish third, with Frenchman Gregory Bourdy and Peter Uihlein of America a further shot back on 13 under.

Down man Cormac Sharvin carded a second successive 72 to finish one under overall for a share of 52nd place.

Oosthuizen saw his three-shot overnight lead quickly cut to one thanks to a bogey on the second as Scrivener and Uihlein made early gains, with France's Romain Wattel holing a brilliant putt for eagle on the third.

South African-born Scrivener had a brief share of the lead after some trouble from a bunker on the seventh but Oosthuizen repeated the trick from the same hazard just minutes later to get back in front.

That birdie seemed to spur the eventual winner and he put his tee-shot on the par three next to seven feet and rolled in the putt to get to 16 under.

That proved enough for a three-shot lead when Scrivener left his par putt on the ninth short but Uihlein - after brushing the hole on numerous occasions - got one to drop for a birdie and the gap was two shots at the turn.

The trio of Scrivener, Uihlein and Wattel saw their challenges fade playing down the back nine and, when Oosthuizen put his tee shot to 10 feet on the 12th, the lead was extended to four shots.

Levy hit a brilliant second into the 18th to set up a birdie and card a 66 leaving Oosthuizen with a two-shot lead to protect up the stretch, which he did with a single bogey on the last.

The Frenchman's closing round contained an impressive eight birdies but was damaged by a double-bogey on the sixth, while a birdie-birdie finish helped Scrivener come home third.

Bourdy, who was right on the cut-line at the halfway stage but went 65-66 over the weekend, finished in contrast to Uihlein, who cut a frustrated figure making a second-consecutive 71.

Allianz EurOpen Strasbourg 2010 winner Wattel finished 12 under, a shot clear of Perth native Brett Rumford, with Singapore's Mardan Mamat at 10 under in eighth.