Top-ranked Lydia Ko was at the top of the leaderboard with Hyo Joo Kim on Friday after two rounds of the Marathon Classic in Sylvania, Ohio.
Ko managed to contend with the windy conditions at Highland Meadows to shoot a 5-under-par 66 for a 36-hole total of 8-under 134.
Kim, who shared the first-round lead with Mirim Lee and Haru Nomura, followed her opening 66 with a 68.
Alison Lee and Ha Na Jang were one shot behind the leaders in a tie for second at 7 under. Lee finished the round with three birdies for a 66 and Jang had a 67.
The 19-year-old Ko, who tied for third last week at the Women's U.S. Open and won a major championship earlier this year at the ANA Inspiration, completed her round with six birdies and one bogey.
"In this wind and in the conditions, I feel like my score is a pretty solid one this morning," Ko said.
Ko started on the front nine and had three birdies and one bogey before coming in with three birdies on her final nine.
"I started off well with a birdie on my first hole, and then made a clumsy bogey on the next hole. I hit a few good shots in. I had a few birdies where it was 3, 4, 5 feet. When you got those birdie chances it makes it a whole lot easier."
Kim was pleased with her round. The South Korean, who won the LPGA Tour's season-opening tournament in the Bahamas, had four birdies and a lone bogey.
"Yesterday was way better," Kim said. "Still today, I played great."
Lee and Nomura dropped into a tie for fifth at 5 under with Azahara Munoz, Vicky Hurst, Stacy Lewis and Kelly Shon.
U.S. Women's Open winner Brittany Lang was 3 under after a 69 and second-ranked Brooke Henderson was 2 under after a 72.
Defending champion Chella Choi failed to make the cut after a 74, and Michelle Wie also went home after a 77.