Kuala Lumpur - Australia's Marc Leishman unleashed an early birdie barrage as he romped home by five shots to claim top place in the $7 million CIMB Classic on Sunday.

At the par-72 TPC Kuala Lumpur, Leishman closed with a seven-under par 65 to finish the only PGA Tour event in southeast Asia at 26-under par 262 for his fourth win on the PGA Tour.

His effort was five shots better than Argentina's Emiliano Grillo (66), and the American duo of Chesson Hadley (66) and Bronson Burgoon (68) - all of whom finished on 21-under par 267.

Two-time champion and former world number one Justin Thomas (64) closed with three birdies in his last three holes to surge up the leaderboard and finish in tied fifth place at 268, where he was joined by Mexican Abraham Ancer (65), South Africa's Louis Oosthizen (69) and fellow Americans Charles Howell III (67) and Gary Woodland (71).

The world number 24 Leishman won the Arnold Palmer Invitational and the BMW Championship in 2017 and continued his winning streak in 2018 with the CIMB Classic win. It all would have looked a distant dream when the 34-year-old almost quit the game around the time of the 2015 Masters, when his wife Audrey was diagnosed with and nearly died from acute respiratory distress syndrome and toxic shock syndrome.

An emotional Leishman, who made eight birdies, including a putt from nearly 50 feet on the par-4 ninth, and a solitary bogey, said it felt "unbelievable" to win.

"It was a very tough time that we went through, but it certainly made us stronger as people, made us appreciate just the everyday things, appreciate our kids more, appreciate friends, family, everything," he said of his wife's illness.

"I won't say it made golf less important, but it made me realize that golf's not life or death... As long as I give it my best shot, that's what it's all about."

Leishman opened with a par and then made four birdies in the next four holes to pull ahead. A brace of birdies on the ninth and 10th had taken him to 25-under par, with none of his closest pursuers putting any pressure on him.

Overnight joint leader Shubhankar Sharma of India started in a shaky manner before coming back strongly with four birdies in four holes from the eighth onwards, but he made three straight bogeys from the 11th to finish on even-par for the day.

Woodland also had an up and down round and never got going.

Grillo could have had a much better finish -- but after getting to six-under par for the day after 12 holes, he could not make a single birdie on the last six holes.

The 26-year-old Argentine said: "I played very well, I shot 30 on the front nine. I started thinking if I could shoot seven-under, it would give me the chance. Unfortunately, I wasn't able to play as well on the back nine, but four rounds in the 60s is always good."

Hadley, 31, made a double bogey on the ninth hole, but four birdies on the back nine resurrected his round, and he was delighted with his finish after a poor run of form lately.

"Delighted like you wouldn't believe. I haven't been playing well for a while and to have a good tournament like this is really nice," said the 2014 Puerto Rico Open champion.

Burgoon, who led after the opening day with a 63, recorded only his third top-10 finish in three years on the PGA Tour.

The PGA Tour next moves to Korea for the CJ Cup.

Leading final-round scores in the $7million CIMB Classic on Sunday at the par-72 TPC Kuala Lumpur:

262 - Marc Leishman (AUS) 68-62-67-65

267 - Emiliano Grillo (ARG) 66-68-67-66, Chesson Hadley (USA) 67-68-66-66, Bronson Burgoon (USA) 63-69-67-68

268 - Justin Thomas (USA) 66-69-69-64, Abraham Ancer (MEX) 67-68-68-65, Charles Howell III (USA) 69-67-65-67, Louis Oosthuizen (RSA) 66-68-65-69, Gary Woodland (USA) 69-61-67-71

269 - Kevin Chappell (USA) 66-67-71-65, Siwoo Kim (KOR) 67-71-66-65, Shubhankar Sharma (IND) 67-64-66-72

270 - Kyle Stanley (USA) 72-68-66-64, Byeonghun An (KOR) 66-70-68-66, Paul Casey (ENG) 66-65-71-68, JB Holmes (USA) 67-67-67-69, Stewart Cink (USA) 68-70-63-69, Austin Cook (USA) 64-68-68-70

271 - Keegan Bradley (USA) 70-67-68-66, Kevin Na (USA) 68-67-67-69, Nick Watney (USA) 66-67-68-70

272 - Keith Mitchell (USA) 70-65-71-66, John Catlin (USA) 73-65-67-67, Cameron Smith (AUS) 69-69-66-68

273 - Xander Schauffele (USA) 69-71-65-68

274 - Joel Dahmen (USA) 66-68-69-71

275 - Kevin Tway (USA) 70-67-71-67, Gaganjeet Bhullar (IND) 69-70-71-65, Scott Piercy (USA) 65-67-71-72

276 - CT Pan (TPE) 65-73-70-68, Thomas Pieters (BEL) 70-69-71-66, Beau Hossler (USA) 72-65-66-73

277 - Ryan Palmer (USA) 68-69-70-70, Billy Horschel (USA) 65-69-73-70, Ryan Armour (USA) 69-72-69-67, Kiradech Aphibarnrat (THA) 69-69-68-71, Danny Lee (NZL) 69-74-68-66, Kelly Kraft (USA) 76-70-66-65

SELECT OTHERS

278 - Jimmy Walker (USA) 73-71-68-66.

279 - Jason Dufner (USA) 70-69-70-70, Satoshi Kodaira (JPN) 71-68-70-70, Justin Harding (RSA) 72-65-73-69, Ernie Els (RSA) 68-72-66-73

280 - Branden Grace (RSA) 70-70-68-72, Sanghyun Park (KOR) 72-68-70-70, Rafa Cabrera Bello (ESP) 73-69-72-66

281 - Ben Leong (MAS) 68-70-71-72

282 - Davis Love III (USA) 70-73-69-70

284 - Pat Perez (USA) 70-69-71-74, Anirban Lahiri (IND) 72-74-68-70

285 - Brandt Snedeker (USA) 75-69-70-71, Ryan Moore (USA) 71-72-72-70.