New Zealand's Lydia Ko fired a 12-under par 60 to seize a one-stroke lead over South Korea's Kim Hyo-joo in Thursday's first round of the LPGA Ford Championship.
Three-time major winner Ko, a 28-year-old Seoul-born Kiwi, shot her career-low LPGA score at Whirlwind Golf Club's Cattail course in Phoenix, Arizona.
With 12 birdies in a bogey-free round, Ko delivered only the eighth 60 in LPGA history and just the third since 2010.
"I holed some putts that I didn't expect to go in and I got a few good breaks and also hit a few good shots. Just a combination where things were going well," Ko said.
"I really wasn't that nervous and nine and eight aren't just gimme birdies anyway, so to birdie those and just finish at 60, I'm excited I finished at that score rather than feeling disappointed that I didn't break 60."
Twelve (12) circles on the card and a new career low.
— LPGA (@LPGA) March 26, 2026
Take a bow, Lydia Ko 👏 pic.twitter.com/DulFLYviuO
The only lower 18-hole score in LPGA history was Annika Sorenstam's 13-under 59 in the second round of the Standard Register PING tournament in Phoenix in 2001 at Moon Valley Country Club.
"Annika is the only one that has shot 59, so any record that matches Annika's record is going to be pretty incredible," Ko said.
"I felt like I gave myself a good run at it and I didn't really feel that much pressure or extra nerves just because I was in that position.
"I think the number 59 did cross my mind by the time I holed my birdie putt on six, but it wasn't like I had a lot of pressure to like break 60. It was just more like oh, it's really cool to be in this position."
World No 8 Ko began on the back nine and birdied her first four holes then added birdies at the 16th and par-five 17th and followed with birdies at the first and par-five second holes.
She closed with two more sets of back-to-back birdies, at the fifth and par-three sixth holes and the eighth and ninth to finish her round.
"I don't think I've ever actually started a round with four birdies, so it was nice to take advantage of the good start and continue that on my back nine as well," Ko said.
"I feel like I stayed patient and was rolling it really well. I actually put in a new putter this week. Like I've had my old putter for a really long time, like the same model, so it was kind of different just to have something else.
"Maybe it's a honeymoon phase. Who knows? But you take a more easy day like this on any occasion."
World No 4 Kim had nine birdies and an eagle in her bogey-free round, which also began off the 10th tee.
She birdied three holes in a row starting at the par-five 12th, then four in a row on holes one through four and then closed with birdies at the par-five seventh and ninth around her eagle at eight.
World No 2 Nelly Korda of the United States was third after firing a 63 with seven birdies and an eagle at the par-four 18th.