World number seven Kim, chasing a wire-to-wire victory at The Colony in Dallas, fired a one-under par 70 to stand on 11-under 202 after 54 holes.
“Carding two bogeys wasn’t a good start for my momentum,” Kim said. “In the back nine, I think my shots came back and was able to end with a good score so I hope to continue that momentum tomorrow.”
Kim, a five-time LPGA champion, has five top-five finishes this year without a triumph, last winning in April 2022 at the Lotte Championship in Hawaii.
“I’m sure as I’m playing tomorrow, the thought of winning will pop up in my head,” Kim said. “But I just want to do my best to play the way I’m satisfied with and the way I want.”
Australia’s Sarah Kemp fired a 69 to share second on 207 with American Lexi Thompson with Sweden’s Frida Kinhult on 208.
“If my putter can continue to be hot and shoot something in the mid-60s, might be able to get it done,” Kemp said of her chances to win.
Thompson, chasing her 12th LPGA title and her first since 2019, rallied from three bogeys in the first five holes to fire a 71.
“Happy that I got it back to even,” she said. “Overall didn’t move much position-wise, so hopefully just go get it tomorrow.”
Kim began with a two-stroke lead but bogeys at the fourth and par-5 sixth left her level with Paraguayan rookie Sofia Garcia.
Kim birdied the eighth while Garcia made bogey to restore Kim’s lead, which grew to three strokes when Garcia made bogey at the par-3 11th.
That remained the margin after Kim followed a birdie at the par-5 13th with a bogey at 14.
Kim responded with birdies at 15 and 16 to reach 11-under, stretching her lead to five strokes, and closed with back-to-back pars.
“I have to play better than today and not lose my focus,” Kim said of her mindset.
Thompson, who will play next week in the PGA Tour event in Las Vegas, made a birdie at the sixth to end her horrid start.
She began the back nine with a birdie and answered a bogey at 14 with birdies at 15 and the par-5 17th to stay in the hunt.
“Really all I can do is focus on my game and emotions and whatever happens I’m going to be proud of myself,” Thompson said.
Kemp’s roller coaster round included five bogeys, five birdies and an eagle at the par-4 15th.
“Just happened to play it perfectly,” Kemp said. “Got a great bounce from the front of the green and I had maybe five feet for eagle, so that was awesome.”