- Golf Australia photo

And as worthy a winner as the brilliant young Queenslander is, a seemingly simple two-shot margin at Kooyonga will not tell the tale of a final day of high drama.

The Brookwater member, just 19, made a birdie of the highest quality on the 17th hole to put his stamp on the national title he adds to the New Zealand Amateur crown he won in 2016.

Before that, he and South Australia’s great hope Jack Thompson had waged an extraordinary war; and all of that while young New South Welshman Jeffrey Guan nearly came from the clouds to beat them both.

Thompson had begun the day with a seemingly insurmountable five-stroke lead and was joined on the fairways by hundreds of Adelaide fans who’d come out to see the expected coronation march.

But Thompson, a member at The Grange nearby, made three nervy bogeys in succession to open his round that immediately enabled Queenslander Dobbelaar to get a foothold in the contest, even though he couldn’t find a birdie.

In fact, it was a miraculous sand save for par on the treacherous fourth green that actually boosted Dobbelaar’s chances.

Even though Thompson made birdie at the same hole to steady his own listing ship, his rival seemed to find strength in the rescue mission he began in the front bunker, 20m short of the flag, then finished with the putter from 4m above a treacherous pin.

“It definitely could have got away there, but I was able to manage to get the gap close pretty quick and that was a pretty important putt,” Dobbelaar said.

Similarly, he later made a key par putt on the top of Thompson’s birdie putt on the short 14th hole.

At the same time, Sydney prodigy Guan joined the lead when he chipped in on the 15th and then birdied the 16th.

But, like Thompson 30 minutes later, Guan came to grief on the 17th when his approach trickled into the treacherous back bunker and all but forced him into a bogey that led to his demise.

Thompson, though, had a more spectacular final capitulation.

With Dobbelaar one in front and having played into birdie range on the 17th, the South Australian went for broke and twice drowned his approach into the front right pond.

His quadruple-bogey was the final straw in his closing 82, a full 17 shots off his course record 65 on Wednesday.

“There’s not much you can do. I’ve said to people who’ve offered their condolences that I’m still fine, healthy and have my friends and family,” Thompson said.

“Obviously it sucks, but I’ll be fine.

“I’d like to think that I kept my head. Early on I might have dropped it, but I really wanted to keep my demeanour, my posture and stay upbeat, so I hope it looks like that from the outside.

“It was incredible to have so many people out here and I can’t thank everyone enough. I could feel the support.”

Thompson’s day went from bad to worse when he made an inadvertent error with his scorecard and was ultimately disqualified.

But none of that should detract from Dobbelaar, who was full value for his 70 today and was the only player to shoot four sub-par rounds.

He narrowly missed birdie tries on many holes and struck the ball well enough to probably have gone even lower had it not been in a pressure-packed situation.

“This is special. I don’t know if it has sunk in yet,” he said.

“I played some pretty good golf at times this week and I know how well Jack and others played, so I’m pretty excited to have my hands on the trophy.”

Guan was enormous, belying his 16 years.

For the second time this week, The Australian member made a string of birdies and despite his bad luck on the 17th, he showed he will be a force in years to come with some level-headed decisions at crunch time.