Ashleigh Buhai was overcome with emotion after surviving an afternoon of chaos to win the Australian Open and achieve a feat not even Cameron Smith can claim.

The South African prevailed after a dramatic collapse from Sydney prodigy Grace Kim to dash local hopes for another year on Sunday.

Buhai closed with a one-over-par 73 at Victoria Golf Club to post a nerve-wracking one-stroke victory over Korean former world No.1 Jayai Shin (75).

With a 12-under 72-hole total of 277, Buhai completed a rare British Open-Australian Open double, having also triumphed at Muirfield to clinch her maiden major championship in July.

Buhai holds up the trophy after triumphing at the Australian Open at Victoria Golf Club. Photo: Getty

Smith arrived at the world-first dual-gender Open a warm favourite to add the Stonehaven Cup to the Claret Jug he famously drank from at St Andrews this year.

But the world No.3 didn’t even make the Saturday cut of the men’s Open, finishing in a share of 47th place.

There was no denying Buhai.

“It’s the cherry on the top,” the 33-year-old said of her triumphant season before choking back tears.

“Sorry, it’s just hit me.”

Kim stumbles on 17th, 18th

Barely half an hour earlier, 21-year-old Kim had stood on the 18th tee sharing the lead and looking every bit the potential champion.

But the new LPGA Tour graduate had to settle for outright fourth at nine under after making a mess of the par-5 18th to chalk up a gut-wrenching double bogey and sign for a last-round level-par 72.

The former Australian amateur champion confessed to also losing her nerve after accidentally catching a peep of the leaderboard on the par-5 17th, where she also blundered by needing two shots to get out of a greenside bunker.

“I didn’t know there was (a leaderboard) there,” Kim said.

“I knew I was playing good because it was tough for everyone, but I think that got me, definitely, mentally.

“That cost me a little bit. But it’s a lesson, so it’s all right.”

South African Buhai plays a shot out of the rough during the fourth round. Photo: Getty

Celebrated compatriot Hannah Green (74) birdied the last to pip Kim for third at 10 under, but the emerging star insisted she would have been happy just to make the Saturday cut before the tournament began.

Green’s winning hopes evaporated on the front nine.

After starting the day two shots off the lead, she recorded two doubles and a bogey to spiral from 12 to eight under and out of contention, six strokes adrift of Buhai heading to the back nine.

Fellow heavyweight Minjee Lee (71) finished fifth at eight under but also must be wondering what might have been.

With an ugly double-bogey seven at the eighth, she spoiled a golden start of three birdies in six holes that had rocketed the world No.4 into contention.

The US Open champion was never a factor after falling seven shots behind Buhai at the turn.

No Australian woman has won the Open since the legendary Karrie Webb reigned for a fifth time at Victoria in 2014.

Webb emerged from semi-retirement to play this week’s special event, rising to the occasion to make the top-30 cut and finish joint-26th.

-AAP