Hannah Green got off to a hot start on the way to a five-under-par 66 that gave the Australian a three-shot lead on Friday midway through the LPGA Palos Verdes Championship.
Green, who started the day four shots off the overnight lead of compatriot Minjee Lee, wasted no time gaining ground with birdies at the first three holes on the par-71 Palos Verdes course south of Los Angeles.
She added birdies at the sixth and seventh and bounced back from bogeys at 12 and 13 with two more birdies at the 14th and 16th.
"I had a lot of close wedge shots today, which was nice because I feel like that hasn't been the strongest part of my game of late," Green said.
"I started with three birdies and the longest putt I had was five feet so that's always nice," added the Australian, who needed just 25 putts overall.
"I made a couple of errors coming in," added Green, who said the gusty afternoon wind made club selection tricky. She was in bunkers at both the 14th and 16th but got up and down for birdie at both.
"Hopefully I can keep as many bogeys off the scorecard and keep making birdies because I think there's going to be some low scores."
Green was three strokes clear of a quartet of players that included overnight leader Lee, world number one Ko Jin-young of South Korea, New Zealand's Lydia Ko and American Megan Khang.
Lee's two-over 73 was 10 shots worse than her opening round, her lone highlight an eagle at the seventh to go along with four bogeys.
Lydia Ko shook off an early double-bogey to bag five birdies and an eagle in her four-under-par 67.
Ko Jin-young, who started the day one off the lead, also had an early double-bogey, and managed just one birdie in her one-over 72.
Khang, meanwhile, joined the group sharing second on 136 with a two-under-par 69 that featured five birdies and three bogeys.
Green, seeking her third LPGA tour title, is coming off a runner-up finish to Nasa Hataoka in the LA Open last week.
She wasn't so sure that was a strong sign for this week, since both of her titles came in weeks after she had missed a cut.
"I feel like I've been hitting the ball really good. This week I feel like I've hit it a lot closer. I'm excited to see what the weekend brings."