WATCH: Hole-in-one keeps An on top Down Under

They are one shot clear at eight-under-par from in-form Matt Kuchar who is lurking dangerously with his confidence surging after winning in Mexico last week.

Amateur David Micheluzzi, playing only his second professional event, and fellow Australian Jake McLeod are alongside the American world number 29.

Another American, Keegan Bradley, who won the BMW Championships this year, made his move with a 66 to be two behind the leaders in a group of seven including Mexico's Abraham Ancer and Japanese amateur Keita Nakajima.

South Korea's An, who like Kuchar plays on the US PGA Tour, hit a seven iron on the short par-three 15th at The Lakes course in Sydney and couldn't believe his eyes when it dropped in the hole.

They are one shot clear at eight-under-par from in-form Matt Kuchar who is lurking dangerously with his confidence surging after winning in Mexico last week.

Amateur David Micheluzzi, playing only his second professional event, and fellow Australian Jake McLeod are alongside the American world number 29.

Another American, Keegan Bradley, who won the BMW Championships this year, made his move with a 66 to be two behind the leaders in a group of seven including Mexico's Abraham Ancer and Japanese amateur Keita Nakajima.

South Korea's An, who like Kuchar plays on the US PGA Tour, hit a seven iron on the short par-three 15th at The Lakes course in Sydney and couldn't believe his eyes when it dropped in the hole.

"It's my third (of career) and the first one with a prize," said An, who began the day with a one-shot lead and finished with a three-under 69 to stay on top.

"I hit a soft seven-iron. I hit it good, everything was perfect. Fading from the left to the hole and went in!"

McCardle joined him as overnight leader after back-to-back birdies on the closing holes in his 66.

Kuchar hit seven birdies and two bogeys for his 67, with conditions much friendlier than the howling wind that caused havoc on Thursday.

"I'm awfully pleased with my positioning, pleased with the state of my game, very much looking forward to the weekend, keeping myself in contention and trying to go back-to-back," he said.

Kuchar's title at the Mayakoba Classic in Playa del Carmen on Sunday was his first tournament win in four years, and he has never gone back-to-back before.

"There's confidence and the confidence comes from some good play," he said.

For Micheluzzi, who plans to turn professional next year, just playing the Australian Open is a dream come true, and being in touch with the leaders is an added bonus. 

"To play in an Australian Open's just awesome. I've been dreaming about it since I was a little kid. This is my first one, so the nerves are still there," said the 22-year-old.

"But I'm trying to do everything just to try to take my mind off it and just play golf, which I really enjoyed today."

An amateur hasn't won the Stonehaven Cup since Aaron Baddeley held off Greg Norman and Nick O'Hern at Royal Sydney in 1999.

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