The South African, who finished runner-up in the Masters to American Bubba Watson in a playoff, registered a total of 17-under 271, three ahead of Britain's Stephen Gallacher.

The 2010 British Open champion, who made a 30-hour journey from Augusta National to take part in the $2.5 million event in the Malaysian capital, fired a four-under 68 in the final round to win his fifth European Tour title.

"It would have been better if I had the green jacket," said Oosthuizen, whose daughter rushed out to congratulate him after the win, with a laugh.

"I thought I was going to be a lot more tired. It was a long journey to get here and I have to be honest and say that I didn't expect to play this well because of the tiredness." Having the family around in the Malaysian capital meant he got little sleep and struggled to get over the jetlag, but yesterday he was not complaining.

"The one thing I did know was that the game was there so that helped a lot," he said.

"I was pretty tired at points in those first couple of rounds but overall it has been great and I am over the moon with the result.

"It was just a question of whether or not I would be able to go all the way physically.

"I didn't want to come here and play bad but to win means a lot because I have been playing well for the last few weeks now and to win gives me a lot of confidence for the rest of the season."

The 29-year old Oosthuizen had to return to the Kuala Lumpur Golf & Country Club early yesterday to complete the remaining eight holes of his third round after thunderstorms and rain had ended play early for the second consecutive day on Saturday.

Gallacher, 37, who signed a wrong score in the morning during his third round, hit a bogey-free round of two-under 70.

"I'm pleased with myself, only a couple of bogeys throughout the whole week and even threw in a shot which wasn't there," Gallacher said.

"Signed for a wrong score this morning. Apart from that, I kept my head. I'm quite proud of myself for that."

Rafael Cabrera-Bello of Spain, Danny Willet of England and Asian Tour rookie David Lipsky of the US shared the third spot, five shots behind Oosthuizen.

2011 Masters champion Charl Schwartzel of South Africa finished sixth while Germany's former world No. 1 Martin Kaymer finished tied seventh at nine-under.

In Hilton Head Island,   South Carolina, Carl Pettersson birdied five straight holes on the front nine and finished with a birdie on the 18th hole for a 5-under 66 and a one-stroke lead over Colt Knost on Saturday after the third round of the RBC Heritage.

Pettersson held a three-stroke lead through 10 holes, yet was tied with Knost after the 15th. Pettersson moved in front with the round's final putt, an 8-footer for birdie on Harbor Town Golf Links signature closing hole. He had a 12-under 201 total

Knost's roller coaster of a round included an eagle on No. 2 and several missed fairways on the tight holes. Still, he kept close enough with a 69.

Zach Johnson, the 2007 Masters winner, shot a 66 to move to third at 8 under. Two-time RBC Heritage champion Boo Weekley had a 70 and was 7 under. Defending champ Brandt Snedeker (69), Kevin Na (70) and Robert Garrigus (70) were next at 6 under.

World No. 1 Luke Donald failed to make a move toward keeping the top spot, his even-par 71 leaving him at 2 over and tied for 52nd. Donald needs to finish eighth or better to fend off No. 2 Rory McIlroy, who like Masters champion Bubba Watson and most other top players, took the week off.