Poland's Adrian Meronk drained an eagle putt at the last hole for a five-stroke win in the Australian Open, while South Africa's Ashleigh Buhai held on to win the women's tournament in Melbourne on Sunday.

Meronk, the world number 56, confirmed his victory with a putt from off the 18th green to finish a clear winner over his golfing idol Adam Scott at Victoria Golf Club.

The giant Pole carded his eagle and four birdies to finish at four-under 66 and pull away from former Masters champion Scott, who lost his winning chance with a double-bogey six at the 17th hole.

"I’m super excited and to finish like that on the 18th hole is just unreal," Meronk said.

"I felt really good again today. I kept doing what I’ve done the last two days and it worked pretty well.

"I’m super proud of myself, proud of my team and super happy right now."

Meronk made history by becoming the first player from Poland to win on the DP World Tour with victory in this year's Irish Open by three strokes after finishing joint runner-up at last year's Italian Open.

He zoomed into contention with nine birdies in a course record-equalling seven-under 63 in Saturday's third round and was rock solid throughout the final round.

The Pole overcome a horror start in his opening round on Thursday, falling to four-over par through his opening seven holes before he clawed his way back into the tournament to claim an emphatic victory.

Despite an eagle finish on the final hole in the second and third rounds to take the overnight lead and driving consistently well off the tee, Scott struggled to give himself enough good looks at birdie putts as he chased his second Australian Open title.

British Open champion Buhai held off the fast-finishing Jiyai Shin to win the women's tournament by one shot.

Buhai, the world number 28, led by four shots at one stage but had to withstand a big finish from the South Korean, who had an eight-foot putt on the final hole to force a play-off, only to narrowly miss.

Australia's Grace Kim was tied for the lead going to the 18th hole before a double-bogey seven dashed her late flurry.

Buhai carded four birdies and five bogeys to finish with one-over 73, but it was still enough to claim victory.

"It’s the cherry on the top," Buhai said. "And to have my husband Dave on the bag, it’s very special to be able to celebrate together," Buhai said.

"He was good today. It was a bit easier for him being inside the ropes than outside the ropes. You’re a little bit more in control.

"Got lots of friends and family here, it’s very cool.”