Lydia Ko's record-breaking start to the Australian Open in Canberra today had playing partner and world No.1 Yani Tseng reaching for the superlatives as the Kiwi teen surged to the outright lead. 

The 15-year-old produced another jaw-dropping performance at Royal Canberra as the world's leading amateur carded a magnificent 10-under 63 - the lowest round of her career -- to hold a one stroke advantage over Colombian Mariajo Uribe. 

Buoyed by her history-making New Zealand Open triumph at Clearwater last Sunday, Ko is now on course for a fourth professional title - or at least a significant improvement on her 19th placing when the tournament was held in Melbourne last year. 

Ko amassed 11 birdies to make an imposing start to the season-opening $A1.2 million LPGA co-sanctioned tournament, an assault that left Tseng awestruck. 

"I feel I'm getting old," said the 24-year-old from Taiwan, a two-time Australian Open champion.

"She just looks like a child, she still looks like 15 but, the way she's playing golf, she looks like a pro." 

The diminutive right hander opened on the back nine with a bogey five - though that setback was far from an ominous sign.

Ko displayed no signs of anxiety despite being featuring in a marquee group alongside Tseng and former teenage prodigy Michelle Wie.

She parred the next and then embarked on a sequence of four straight birdies - a run stunted by the highlight of her round, an eagle on the par-5 15th.

The self-effacing Ko was all smiles when a wedge from 89-metres bit and spun back to plop in the hole, and although she immediately surrendered a stroke with a bogey on the next the subsequent 11 holes contained just one more blemish.

Ko, who became the youngest ever winner of an LPGA Tour event when claiming the Canadian Open last year, needed just 30 strokes to complete the back nine as she dominated her high profile playing partners with a round that represented a two shot improvement on her previous best.

"I was in a really good group to start off with. I was pretty nervous when I saw the draw and that I was playing with two big names but it was fun out there.

"Yani and Michelle, we had really good conversations so I think it made it more enjoyable."

Incredibly it took until the 10th for Ko to register a par; she then birdied four of the next five holes to drop to 10-under with three to play.

Ko dropped a shot when misjudging the par-3 eighth but regained her composure to close out by beating par one last time.

Tseng was left in Ko's wake at 5-under while Wi - an idol of Ko when she was growing into the game - signed for a mediocre 1-over 74.

Uribe provided the closest challenge to Ko thanks to a bogey-free round complemented by seven birdies and an eagle on the par-5 sixth.

Tseng kept pace with Ko before the turn by fashioning five birdies but then slipped into solid par-gathering mode and completed seven front nine holes in regulation to provisionally sit in a share of seventh.

Wie's round was effectively over after the American trudged off the par-5 18th weighed down by a quadruple bogey nine.

South Korea's Mi Hyang Lee and Ayako Uehara (Japan) were three strokes adrift on Ko in a tie for third as the round continued.

The Open, co-sanctioned between the Australian, European and United States LPGA Tours, features nine of the world's top 20-ranked professionals.

- © Fairfax NZ News