Jiyai Shin plays relentless golf, splitting fairways and hitting greens with almost monotonous regularity. Lydia Ko, nine years her junior but also Korean-born, plays to the same game plan, brilliantly simple in its concept and execution. Tomorrow they will duel head-to-head for the ISPS Handa Women`s Australian Open at Royal Canberra.

Five months ago in British Columbia Shin and Ko went down the stretch in the Women`s Canadian Open with the teenage wunderkind achieving an historic triumph, at 15 years and four months the youngest-ever winner on the world`s most lucrative tour, the LPGA.

They are tied for the lead at 17-under-par after an enthralling third round in gorgeous sunshine at Royal Canberra today. World No. 8 Shin, playing in the last group with overnight leader Mariajo Uribe, was steady all day, carding a three-under par 70. The highlight of her day was a holed bunker shot from beside the par-five sixth green, from a trap so deep that she did not even see the ball disappear into the hole. \"I was too short to watch it!`` she said later.

Ko, playing in the second-last group started quickly with four birdies in the first 10 holes to take the lead, wobbled with bogeys at the 12th and 14th holes, then closed with a birdie at the 18th to tie Shin. She also shot 70 for the day.

It looks to be a two-horse race. Spain`s Beatriz Recari, at 11-under, is the closest pursuer, six shots back. World No. 1 Yani Tseng needs a miracle round at nine-under, eight back from the lead. The nearest of the Australians is Sarah Jane Smith at eight-under after an even-par round today.

The pair know each other well. Shin grew up in Korea and now lives in America; Ko moved from Korea with her family to New Zealand when she was seven. Shin said earlier this week that Ko`s presence made her feel old at 24; she is not alone among the professionals in feeling that. \"I`m young, too!`` said the elder player. \"She`s just a baby!``

For her part, Ko acknowledges two-time major winner Shin`s record in the game, and that there are similarities in their approaches. \"They say we look alike too,`` said Ko. \"She`s a pretty accurate player off the tee. In that way we could be similar. She`s a great player and there are things I do need to learn from her.``

Ko revealed some fragility on the back nine, with a poor drive into the trees at the 12th giving her a bogey, and at the par-four 14th she was long with her approach then fluffed the chip back from long rough, needing to make a 2.5 metre putt for bogey. \"They were pretty hard shots to make up-and downs,`` she said later.

But the 15-year-old winner of three professional tournaments gathered her faculties, donning an ice scarf to cool herself down, and a 90-metre pitching wedge shot at the last hole stopped in the shadow of the flag for the birdie she needed to regain a share of the lead with Shin.

As the hot sun baked the Royal Canberra greens there was some carnage today. Overnight leader Uribe topped her second shot on the first hole, scuttling a fairway metal shot just 100 metres along the ground, and immediately took her first bogey of the week. Uribe had said on Friday night that she loved playing under pressure; now she would feel it like a lead weight. She went backwards, carding a six-over par 79.

Nor did Australia`s Kristie Smith back up her fine form of the opening two days. Playing alongside Ko with the biggest gallery of the day, Smith shot a four-over 77 to fall out of the running.

The astonishing Ko would be the youngest-ever winner of a Women`s Australian Open if she hit the finish line first tomorrow. She would also forgo another $180,000 in prizemoney because she remains an amateur. But nothing much fazes her; certainly not that. \"I don`t really care any more,`` she said. \"I`m an amateur, so I know I`m not going to get it.``