CANBERRA (AP) - South Korean-born 15-year-old Lydia Ko shot a 10-under 63 on Thursday to take the first-round lead in the LPGA Tour's season-opening Women's Australian Open.
The New Zealand-based amateur won the New Zealand Women's Open last Sunday for her third victory in a professional tournament.
Last year, Ko won the New South Wales Open in Australia to become the youngest player to win a pro tour event and the Canadian Open to become the youngest LPGA Tour winner. She also won the US Women's Amateur.
Ko opened with a bogey on the 10th hole, birdied the next four holes and eagled the par-five 15th. She bogeyed the 16th and birdied the 17th and 18th to make the turn at six-under 30 at Royal Canberra.
Ko added birdies on No. 2, 3, 4 and 6, dropped a stroke on No. 8 and closed with her 11th birdie.
"I was in a really good group to start off with," said Ko, grouped with top-ranked Tseng Ya-ni and Michelle Wie the first two rounds.
"I was pretty nervous when I saw the draw that I was playing with two of the big names, but I mean the weather was beautiful. I think we all enjoyed our time out there."
While still in high school, she hasn't had time to spend in class this year due to her golf commitments.
"I've got the Thailand Open next week and then the New Zealand LPGA Championship," Ko said. "After that, I will start opening books."
Colombia's Mariajo Uribe was a stroke back while South Korea's Jiyai Shin was two behind after a 65.
Tseng, the Australian Open winner at Commonwealth in 2010 and 2011, opened with a 68 in her first tournament of the year. Wie, making her first appearance Down Under, shot a 74.