Jessica Korda birdied three of her last four holes to keep her nose in front at the LPGA Los Angeles open, where she led world number one Ko Jin-young by one stroke after three rounds on Friday.
Korda fired a three-under par 68 at Wilshire Country Club for a 54-hole total of 16-under par 197.
“I’m just trying to be patient,” Korda said. “It’s tough. It’s tough to win out here. Still have 18 holes left and I just want to give myself an opportunity to win.”
A bogey at the par-three 18th saw South Korea’s Ko fall one behind after her five-under 66 for 198. Korda, ranked 21st in the world, held a three-shot lead going into the second round and looked like making it a runaway when three straight birdies to open the round pushed her advantage to six strokes.
But she dropped three shots in the space of five holes in the middle of her round and Ko stepped on the accelerator with a run of five birdies in six holes - at the fourth, fifth and sixth and eighth and ninth.
“Honestly, it’s just hitting it in the right spots,” Korda said. “Pins were definitely tougher today than they have been the last two days, more tucked, so it was hard to be aggressive on a lot of them.”
On a back-and-forth back nine, Korda still held a one-shot lead as the last-group playing partners arrived at the 13th, where Ko’s birdie coupled with Korda’s bogey saw the South Korean take the lead.
Ko added birdies at 14 and 15, but Korda wouldn’t go away, nabbing birdies of her own at 15 and 17. Down by one arriving at the par-three 18th, Korda gave herself a four-foot birdie chance while Ko missed the green and saw her first chip up to the putting surface roll back to her feet.
Ko would eventually curl in a long putt for bogey - her fourth of the day - before Korda stepped up to make her birdie putt and regain the lead.
“It was fun and I had a lot of chances for birdie. I had great round still,” Ko said. Canadian Brooke Henderson was alone in third after a four-under par 67 for 201.
Henderson bounced back after a double bogey six at the sixth hole with six birdies the rest of the way, including three in her last four holes.
“I didn’t really do anything wrong,” Henderson said. “One shot got away from us and ended up making a big number. So I just tried to stay in the moment and continue to hit good shots.”
It was a further stroke back to American Angela Stanford, who carded a 68 for 202.

Leading scores
(USA unless noted, par-71)
197-Jessica Korda 64-65-68
198-Ko Jin-young (KOR) 67-65-66
201-Brooke Henderson (CAN) 69-65-67
202-Angela Stanford 68-66-68
204-Hannah Green (AUS) 68-67-69, Ryu So-yeon (KOR) 68-67-69
205-Morgan Pressel 68-71-66, Tiffany Chan (HKG) 65-70-70
207-Lin Xiyu (CHN) 68-72-67, Lee6 Jeong-eun (KOR) 68-69-70
208-Ashleigh Buhai (RSA) 71-69-68, Pajaree Anannarukarn (THA) 71-68-69, He Muni (CHN) 67-71-70, Gabriela Ruffels (AUS) 70-67-71, Park In-bee (KOR) 68-68-72, Ally Ewing 67-69-72, Austin Ernst 66-70-72