Playing on an invite this week, the South African, once ranked inside the top 100 in the world, clinched a one-stroke victory over Victoria's joint overnight leader Cam John on a whirlwind final day that saw the lead exchange hands numerous times on a cold, wet and blustery afternoon.

Bekker (73-71-68-69) finished at 7-under-par and with an added love of Perth, where he is thinking of relocating his family.

He is the first South African winner of the WA Open since the great Gary Player in 1956.

A fixture at the top of the leaderboard all day after three early birdies, Bekker kept his nose in front of the chasing pack with a clutch bogey putt on the 14th, but the drama really kicked in on the penultimate hole.

Despite pulling his tee shot on the treacherous par-three 17th, which played as one of the most difficult holes all week, a kick off the bank saw Bekker's ball hop right and pull up just a few inches short of the hole.

The tap-in birdie moved him to 7-under-par, but the 40-year-old almost contrived to throw away his advantage on the par-5 18th after coming up just short of the green with his approach.

Bekker's decision to putt rather than chip almost backfired spectacularly, as his effort broke savagely left and ended up on the lip of the deep, left greenside bunker.

With no stance, he was forced to putt down a steep slope left-handed with the back of his flatstick and raced his birdie a good 10 feet past.

Under immense pressure, his breaking par-saver found the middle of the cup to preserve his narrow advantage, eliciting a roar of relief from the normally taciturn South African.

Playing in the group behind, John pulled to within a shot of the lead with a birdie on 16, but a drive into the trees on 18 severely limited his chances of a grandstand finish.

A punch out was followed by a wedge to the back of the green and when John's birdie putt refused to drop, the win was Bekker's – along with a two-year exemption on the Challenger PGA Tour of Australasia.

After struggling with his game for the past few weeks, Bekker said his win was around such a challenging layout was as unexpected as it was welcome.

"This come so far out of left field," he said. "I've missed the last six or seven cuts in a row, but I said to my wife, I feel like [my game's] close and I wouldn't be surprised if I'm playing well one week. This was the week, apparently.

"This golf course is so unforgiving. You've got to play such conservative golf, even with wedges in hand from the middle of the fairway. It was a grind and I’m glad I could stick it out."

Of his final-hole travails, Bekker was able to see the funny side with the trophy safely in his clutches.

"I just hit (the putt) too soft. Somehow it didn't go in the bunker, but I obviously didn't have a stance and had to putt left-handed from there.

"Let me tell you, there were some things that happened that I've never seen in my life. So yeah, it was interesting."

Headline act Marc Leishman (69) was a factor throughout the day and made an early charge from three shots back to take a share of the lead heading into the back nine at 6-under-par for the championship.

However, some uncharacteristic slips on the par-four 11th cost him dearly as he thinned a bunker shot over the green and failed to get up and down.

PLUS...

Bekker embraces a potential new chapter in the West

Oliver Bekker is a well-travelled professional. The South African has seen all sorts of different layouts, but few like Kalgoorlie.

The resulting double-bogey killed his momentum if not his chances, but his clutch birdie putt from 30 feet on 18 was ultimately only good enough for a share of third alongside Lachlan Barker (68) and Nathan Barbieri (69), two back from Bekker's winning total.

Elsewhere, co-overnight leaders Haydn Barron and Jared Edwards were never firing on all cylinders and carded respective rounds of 73 and 74.

Barron shared sixth with fellow West Aussie Curtis Luck at -4, with Edwards in outright eighth a shot further back.

In the concurrent WA Open All Abilities Championship, South Australia's George Vassiliadis reigned supreme after an excellent closing 81.

The 32-year-old, who had shared the lead after Saturday's first round, accelerated away today to win by eight strokes from Mount Lawley's Mark Mosbach.