Meena Lee grabbed a share of the lead of the North Texas Shootout after carding a seven-under-par 64 second round on Friday.
The South Korean carded 10 birdies in her round to reach eight-under after 36 holes at Las Colinas Country Club, alongside Germany's Caroline Masson, who marked her second consecutive 67 on the day.
"I had confidence with my putting, so I made a lot of birdies," Lee said after her round.
"I'm playing well and the course is really good. Good green speeds.
"I made eagle, so started very good, and then my putting was really good. Inside 15 feet for par, almost always made it.
"I had a lot of birdies. My irons were inside 15 feet almost every hole. Everything was on my side on the first nine."
American pair Natalie Gulbis and Stacy Lewis are another stroke behind after rounds of 65 and 64 respectively, while Christina Kim is another shot further behind on six-under.
Suzann Pettersen (71), Paraguay's Julieta Granada (66), Dutchwoman Dewi Claire Schreefel (66) and Americans Dori Carter and Cristie Kerr (both 70) were next on five-under.
Mason notched back-to-back birdies at the second and third, but played controlled golf throughout.
"I started off well again, made some birdies, maybe didn't play as good as yesterday, but I made some good putts and I played pretty consistent," said Masson.
"I'm just trying to enjoy it, have fun, not try to have any pressure get to me, just having a good time."
She made the only bogey of her round on the eighth, but finished with another birdie on the final hole to claim a share of the lead.
"I finished with a birdie, so overall, yeah, I think it's a great day. I just have to keep doing what I'm doing, stay patient. Everything is good," Mason continued.
"I just feel comfortable with my game. It feels like I'm hitting it solid. I don't really mis-hit many shots so that makes me feel pretty confident out there."