South Korea's Mi Hyang Lee, a Monday qualifier whose last LPGA victory came more than five years ago, holds a one-shot lead after the first round of the DIO Implant LA Open, while Leona Maguire and Stephanie Meadow are in a fight to make the cut.
A disastrous back nine means that Meadow has a big battle on her hands to be involved with the weekend action.
There was little sign of what was to come in the early stages of her round as a slow and steady performance say Meadow make the turn in 35, having hit a birdie on the fourth hole.
However things took a turn for the worst on the 11th hole where she started a run that saw her drop right off the pace. Back to back bogeys on the 11th and 12th were followed by double bogeys on the 13th and 14th, while another bogey on the 18th saw her finish the day on +7.
With the projected cut at +2, Maguire looks the more likely of the two to stick around this weekend. She recovered from a double bogey on the second hole. She hit two birdies in her round to wipe that out although a bogey on the troublesome 14th leave her of +1.
At the top of the leaderboard Lee shot a 6-under-par 65, putting her in front of Megan Khang and South Korea's Hyo Joo Kim, who both shot 5 under.
Defending champion Nasa Hataoka of Japan, Lucy Li and Canada's Maude-Aimee Leblanc are tied for fourth at 4 under.
Nelly Korda, Jessica Korda, Amanda Doherty, China's Ruoning Yin, England's Charley Hull and France's Perrine Delacour share seventh place at 3 under.
Lee earned her two LPGA wins at the 2014 Mizuno Classic and the 2017 Scottish Open. She produced a bogey-free round on Thursday, capped by a birdie at thepar-4 18th hole.
The key to her round? "I had a really good caddie," Lee said. "I mean, my friend's dad, so he helped a lot from Monday and today also. So really thanks to him, yeah."
Kim got to 6 under with six birdies and six pars through 12 holes, but after carding her lone bogey at the par-3 13th hole, she closed with five pars.
"It was my first U.S. tournament of the season, and I'm really satisfied that I put up a good score on the first day," Kim said. "The golf course here, the (greens are) actually pretty small and I was really happy with how much I didn't miss the greens today."
Kim said of being in contention, "It's been a while since I've seen my name on the top of the leaderboard so definitely extra motivation to do well in the remaining days as well."
Khang began on the back nine and reeled off three consecutive birdies at holes14-16. She added three more birdies and a bogey on the front nine.
Hataoka and Li each had six birdies and two bogeys while Leblanc finished with seven birdies and three bogeys.
Li said, "I just hit it really well and just kept doing that. ... It was kind of windy on the back nine, so just like managing that really well, judging the distances very well was really good. I had a couple tap-in birdies, which was nice because the greens are pretty tricky."
