Lee Mi-Rim shrugged off an opening bogey to card six birdies in a five-under 67 and seize a one-shot lead after three rounds of the LPGA Kia Classic in Carlsbad, California.
With a 13-under total of 203, Lee was one in front of fellow South Korean Hur Mi-Jung, whose seven birdies in a six-under 66 included three in a row to cap her round.
It was a further two strokes back to Korea's Chun In-Gee, who signed for a 67, and American Cristie Kerr, the overnight leader who bogeyed the last for a one-under 71 that left her tied for third on 206.
Lee, who captured both of her LPGA tour titles in her rookie season in 2014, finds herself in a familiar position.
Two years ago she also held the 54-hole lead, three strokes in front of Kerr -- who went on to win the tournament.
After her bogey at the first, Lee got going with three birdies in a row from the third through fifth holes, and she added birdies at the ninth, 10th and 16th to take the lead as Kerr endured a roller-coaster of a day.
The US veteran had five birdies, but closed the round with the last of her four bogeys.
World number three Chun, who shared the first-round lead before spiraling to a 73 on Friday, clawed her way back up the leaderboard with six birdies in her five-under effort.
"Stay patient," she said of her mind-set, and it paid off with a "really good back nine" for the player whose only two LPGA victories have come in major championships.
Defending champion and world number one Lydia Ko was absent for the weekend action, having missed the cut for just the second time in her LPGA career on Friday.