Harris, the 15-year-old Melburnian, accelerated away from the field today in bleak, blustery and wet conditions at Yarra Yarra, her home course.

A third-round five-under par 68 after she started the day in a share of the lead with Japan’s Aina Fujimoto put Harris six shots ahead with a round to play.

Two eagles – one from close range at the par-5 9th hole and another from longer range at the par-5 16th were the highlight of a day when almost everyone else in the women’s field went backwards.

In the blustery conditions – gusting up to 50 km/h – it was a masterclass from Harris.

By day’s end she was at nine-under for 54 holes, her nearest-challenger being Japan’s Mamika Shinchi at three-under with New Zealand’s Eunseo Choi a further shot back at two-under.

“I was hoping for two-over (today) or better, that would have been good,” she said. “Starting off there was a bit of rain, and I just tried hard to make pars.”

Realistically the championship is hers to win or lose on Friday.

Incredibly, she is a couple of weeks away from picking up the books and going back to school for year 11 at McKinnon Secondary College, not far from Yarra.

She has been on the radar of Australia’s High Performance fraternity for several years now, winning numerous junior tournaments, but this is a national championship in open company with more than 80 overseas players competing.

What a story she has become. Potentially Australia’s brightest prospect since Minjee Lee came out of Perth a decade ago.

How will she handle the final round?

“I’m going to try and play how I did today, fairways and greens and anything can happen tomorrow.

“I would feel pretty good (if I won). It would be my biggest win other than Riversdale (Cup); I’d be pretty proud.”

Queenslander Quinn Croker leads the men's Amateur by 4. PHOTO: Golf Australia.

Queensland's Croker, 21, was just as impressive in reeling in Kiwi overnight leader Mitchell Kale and surging ahead with a six-under 64 which was stunning in the tough conditions.

At 11-under overall, he is four shots ahead of Yarra Yarra's Phoenix Campbell, his main challenger.

Croker was runner-up in the Heritage Classic on the Challenger PGA Tour of Australasia just last weekend, which puts him in a white-hot streak of form.

He is in the national High Performance programs, and he won a tournament in Singapore in 2022, but this would be by far his biggest win.

But to do it, he needs to overcome Campbell, who holds the course record at Yarra.

"It's going to be fun," said Croker.

"He's obviously going to feel pretty comfortable around the golf course and the shots that set up tomorrow.

"I'm going to have to probably bring my A-game to see if I can stay ahead of him after the 72."