Jeeno Thitikul of Thailand carded seven birdies in a bogey-free round of 64 to hold a two-shot lead after the opening 18 holes of the AIG Women's Open at Royal Lytham & St Annes on Thursday in Lytham St Annes, England.
South Korea's Haeran Ryu and Japan's Shiho Kuwaki are tied for second at 5-under 66. Yealimi Noh and France's Celine Boutier are tied for fourth at 4-under 67.
Jeeno, ranked second in the world, is seeking her first major title. Her best finish was second at the Evian Championship in 2025.
"The majors really test our games mentally and physically," Jeeno said. "When you play good in a major, even top five or top 10 ... you feel great and then you have more confidence going to play just regular tournaments. It's about beating the course when you're in a major."
Jeeno made four birdies in a five-hole stretch on the front nine. She added three more on the back nine.
"I do enjoy it when golf is good," Jeeno said. "It's really nice that I knew I hit some good shots, but (I got) lucky bounces over the pot bunkers. When it's your way, it's really your way. I knew I had a really good putter today, too.
Ryu won two of this year's previous four majors -- the Women's PGA and the Evian -- and she started the Women's Open strong with six birdies and one bogey. She had four birdies on the front nine and her lone bogey came on the par-4 15th.
"Today felt so tough because in the morning before the round there was a little rain, so I (thought), ‘Please no rain today,'" Ryu said. "Weather is pretty good and the wind is still hard ... My golf is pretty good."
Kuwaki, 23, is playing just her seventh major. Her best showing was a tie for 14th at the U.S. Women's Open earlier this year.
Like Ryu, she had six birdies -- including on Nos. 16 and 18 to close strong -- with one bogey.
"I managed my game well despite the strong winds and I was able to hole some key putts," Kuwaki said. "I stay focused throughout the round and finished with such a good score.
"My shots were very consistent and making a putt of about six meters early in the front nine really helped me get into a good rhythm."
Noh had five birdies against one bogey while Boutier kept her card bogey-free with two birdies and an eagle on the par-5 sixth.
"I was able to hit a solid 6-iron on my second shot and reach it in two," Boutier said of the eagle. "I had about a 20-footer or so, slightly uphill and right to left, so tried to give it a good run and it kind of like went around the hole and went in, so it was a nice surprise.
"I honestly thought it was going lip out, but, yeah, happy that it went in."
Thailand's Chanettee Wannasaen and Japan's Chizzy Iwai are tied for sixth place at 3-under 68.
Nine golfers are in a logjam tie for eighth at 2 under, including England's Charley Hull and Lottie Woad.
World No. 1 Nelly Korda, who won the first two majors of the season, shot a 2-over 73 and is tied for 53rd place.
Korda recorded bogeys on Nos. 2-3 to dig an early hole. She got back to par with birdies at No. 6 and No. 8 before carding bogeys on No. 11 and No. 15.
Among other golfers, Jennifer Kupcho is tied for 17th at 1 under, New Zealand's Lydia Ko is at even par, Japan's Yuka Saso and Canada's Brooke Henderson are 1 over, Rose Zhang is at 3 over and South Korea's Jin Young Ko is at 4 over.
