Amelia Harris was still smiling on the outside but hurting inside after the 15-year-old Australian succumbed to some nerves and a relentless Japanese opponent on the final day of the adidas Australian Amateur at Yarra Yarra today.

The brilliant young Melburnian began the final round with a six-shot lead but was overtaken by Japan’s 16-year-old Mamika Shinchi after a great battle for supremacy.

Ultimately Shinchi, a winner of at least 20 tournaments who has been ranked 13th in the world, was too good on the day, shooting an equal course record 66 with an incredible 10 birdies.

It put her at 10-under par overall and a winner by two shots over Harris, who shot a 1-over 74 in the final round to finish at 8-under and outright second.

“Obviously it stings a bit,” she said. “But I’m happy with how I finished. It’s my best finish.

“I missed a couple of short putts, on 14, I was kind of mad and I went in the bunker (on 15) and made another bogey.”

But the Victorian will have many more days in this position on the evidence of this week’s performance on the sandbelt.

She was already highly-rated; in the Golf Australia high performance programs and being feted by American colleges. But her performance will have attracted plenty more attention around the world.

Shinchi is the second consecutive Japanese winner of the women’s section of the Australian Amateur was stunningly good when it counted. She made three bogeys on the front nine and was struggling, but picked up shots at 8 and 9 and 10 to get back in the mix.

At the par-5 13th, both players made good birdie putts and the Australian was still a shot ahead, but the turning point came at the par-4 14th. Shinchi hit her short iron shot in close and holed for birdie; Harris hit the green but three-putted and the lead changed for the first time all day.

Harris bogeyed 15 from the left trap and now was two behind.

The young Aussie hit beautiful iron shots in to the last three holes and birdied all three – but Shinchi matched all those birdies to stay in front.

She had six birdies on a back nine of 31, 6-under par, and acknowledged it as her biggest win in golf.

Harris started without a caddie, then asked her father Ritchie and then Shyla Singh, her friend from the Queensland team, to help her.

Shinchi had her Japanese teammate Taishi Moto on the bag all day.

As for Harris, the moments will go into the memory bank.

“It will help a lot,” she said. “It’s good experiencing it being up the top.”

Another Japanese player, Aina Fujimoto, finished tied-third with New Zealand’s Eunseo Cho.

Australian Justice Bosio rallied strongly to finish in the top five.

Final leaderboard.