IN MANY ways, Jiyai Shin will be the villain at Royal Canberra on Sunday, the only person who can prevent the Lydia Ko fairytale most crave.
They will stroll to the first tee deadlocked at 17 under, and will effectively engage in matchplay warfare in the final round of the Australian Open.
Fifteen-year-old Kiwi prodigy Ko and world No.8 Shin put daylight between themselves and the chasing pack with matching three-under-par 70 rounds on Saturday.
Most in the golf world want Ko to win, to write another chapter in an amazing story after winning the New Zealand Open last week.
But it's unfair to tag 24-year-old Shin a villain. She's far too nice. ''I'm still young, too, I'm young,'' she laughed after her third round. ''She [Ko] is just baby, I'm a young girl.''
Lydia Ko and Jiyai Shin are similar in many ways, particularly their Korean heritage. Ko even joked that ''they say we look alike, too''.
But in many respects they're also polar opposites.
Ko is unerringly reserved and composed, never displaying any real emotion, despite her often outrageous shot-making.
Shin wears her heart on her sleeve, her bubbly personality a hit with the Royal Canberra galleries.
That was evident on Saturday when she eagled the par-five sixth with a chip-in from the greenside bunker, but her diminutive frame stopped her from watching it go in.
''I was too short to watch the eagle,'' she laughed. ''I was surprised when I was told it went in, but kind of sad I couldn't see it.''
Despite her reserved nature, Ko has been the headline act this week since her brilliant 10-under 63 on Thursday. But she makes no apologies for her on-course manner. It helps her play her best golf.
''I don't really like to show my expressions a lot, unless it's really big,'' she said. ''There has been times when I've shown emotion and expression. Even if it was good stuff, it's led to not so good hole the one after.''
Shin has been No.1 before, in 2010. Most predict it won't be long until Ko achieves that feat, when she decides to turn professional.
Ko outpointed Shin in last year's Canadian Open, when they played together in the final round, to become the youngest winner of an LPGA event.
''It doesn't really give me an advantage,'' Ko said. ''But I guess I've played alongside her before so it does make it a bit more comfortable.''
Shin said revenge wasn't on her agenda, nor was avoiding losing to a child a second time. She simply wants to go one better than the 2008 Australian Open at Kingston Heath, when she lost in a play-off to Karrie Webb.
''That happened in the past, I'm just thinking about tomorrow. It makes it comfortable for us because I'm just focused on her score and she also, but this course you have a lot of chance to make birdies, so I keep watching other players.''
Ko bounced back from bogeys on holes 12 and 14, finishing with a birdie on the 18th. Shin was solid throughout, birdies on the par-four fifth and par-five 15th complementing her eagle, and a bogey on 17 her only blemish. The pair lead by six strokes from young Spaniard Beatriz Recari (68-69-71) at 11 under.
Ko's amateur status means she will forgo the $US180,000 first prize cheque should she win, after also waving goodbye to $US300,000 at the Canadian Open.
She couldn't care less. ''I don't really care anymore. Because I'm an amateur I'm not going to get it anyway, so what's the point?'' she said. ''I'm just out here for the experience; money doesn't matter to me at this stage.''