Lizette Salas birdied six of the first eight holes and matched fellow American Nelly Korda for the lead after Saturday's third round of the Women's PGA Championship.
Salas fired a five-under-par 67 for the third day in a row to stand level with Korda on 15-under 201 after 54 holes at Atlanta Athletic Club.
Salas sank a 40-foot birdie putt at the opening hole, a four-footer to birdie the second, a 30-foot uphill birdie putt at the par-5 third, a four-footer at the par-5 fifth, a tricky downhill putt at the par-3 seventh and a 15-footer to birdie the 18th.
"I'm really proud of myself for how I started and how I maintained that confidence throughout the round even though putts weren't dropping," Salas said.
"I was committed to each shot, and I wasn't uncomfortable, which I haven't said in a very long time."
Korda, the 22-year-old daughter of retired Czech tennis star Petr Korda, birdied three of the first five holes on her way to a 68.
"Lizette was rolling in some nice ones. I told myself I've got to hit it close to even keep up with her," Korda said. "I told myself to stay patient. There's so much golf left. There's still 18 more holes."
Thailand's 21-year-old Patty Tavatanakit, who won her first major title at this year's ANA Inspiration, shared third on 206 with Italy's Giulia Molinaro and France's Celine Boutier. Tavatanakit shot 65 while Molinaro fired 66 and Boutier 69.
Both Salas, 31, and Korda are seeking their first major titles.
Korda has three top-three finishes in majors, including a share of third at this year's ANA Inspiration after a runner-up effort last year. Her best Women's PGA result was a share of third in 2019.
Last week, Korda won her fifth career LPGA title at the Meijer Classic and she could become the first player since Taiwan's Yani Tseng in 2011 to make the Women's PGA the second of back-to-back wins.
Salas won her only LPGA title in 214 starts in 2014 at Kingsmill. Her best major showing was a runner-up effort at the 2019 Women's British Open.
Salas, who began the day a stroke off Korda's pace, made her sizzling start to reach 16-under, two ahead of Korda, who opened with back-to-back birdies and added another at the par-5 fifth but still lost ground.
"I was embracing it. I was greeting some fans and just enjoying the moment. It has been a while since I've done that," Salas said.
"I got off to a really hot start, and I didn't realize I shot 30 until I signed my scorecard. It's fun when you play like that. It's good momentum going into tomorrow."
Salas opened the back nine with her only bogey of the week after sending her tee shot at the 10th into left rough and having an awkward stance for her second.
"It's a major. You can't make all of them," Salas said. "When I made that bogey, I just said, 'It's OK. There's lots of golf left.'
"Before I would have chewed myself up in my head and said a lot of negative things."
She had managed only three bogey-free rounds over two seasons before this week.
Korda rolled in a five-footer for par at 10 to move one adrift and birdied the 13th to match Salas for the lead.
At the par-3 15th, Korda yelled "water" after hitting her tee shot, but her ball cleared the hazard left of the green and she and Salas each made par.
"There's a lot of water in play here, and there's a lot of really difficult tee shots," Korda said. "If you just miss it by a little, you're in the water."
The co-leaders parred the last three holes as well, Salas sinking the most testing par putt among them from five feet at the par-5 18th.