Taiwan's Lee Min capped her stellar outing on Saturday by rolling in a 15-foot putt for birdie on 18 to grab a two-shot lead heading into the final round of the LPGA Mediheal Championship.
Lee birdied three of her final four holes, including the par-five 18th, for a four-under 68 and a total of nine-under 207.
"I just tried to play my game and tried to be smart on the golf course, because the golf course is very hard," Lee said. "There are some pin placement that you want to be on the fat side of the green if you miss it."
The 26-year-old Lee, who is seeking her first win on the Tour, also made birdie on the par-three 17th and the par-five 15th at the Lake Merced Golf Club just outside San Francisco.
"I just try to play my game. I play well, that's good and everything comes together," she said.
Finland's Matilda Castren, who shot a 69, and Lauren Kim (71), are tied for second.
The 26-year old Kim has exceeded her expectations coming into the week.
"Oh, gosh, probably pretty nervous," she said after being asked what to expect on Sunday. "I never played in the final group on Sunday and am just going to enjoy it as much as I can.
"Coming into this week I was just trying to shoot under par every day, and I've done just that. So hopefully I can get another one tomorrow."
Switzerland's Albane Valenzuela shot a four under 68 to join Kim A-lim (69) at six under.
Second-round leader Danielle Kang stumbled late, making a double bogey on 18 for a 74. Kang is at five under, joining Lindsey Weaver (69), Jenny Shin (70), Jennifer Kupcho (70) and Jenny Coleman (71).
Lydia Ko (70), Patty Tavatanakit (71), Lucy Li (70), Ashleigh Buhai (70) and Yealimi Noh (71) are all at four under.
"Overall I played pretty solid today," Ko said. "Got a few loose ones out there, but at the end of the day I feel like no matter what round you have, you feel like you could have done better."