England's Charley Hull fired a nine-under par 63 to seize a one-stroke lead over Denmark's Nanna Koerstz Madsen after Thursday's first round of the LPGA Ford Championship.
Hull's bogey-free morning round at Whirlwind Golf Club came with a new driver after suffering a "tweaked" club early in the week.
"I really hit it well. I felt like that put me in a lot of good positions," Hull said. "I putted pretty well. I chipped pretty well. I hit it pretty well with my iron shots.
"I don't think I missed a green and didn't really miss any fairways. I was hitting it good and just felt confident."
Hull seeks her third career LPGA triumph and first since the 2022 Volunteers of America Classic. She is also a four-time Ladies European Tour winner, most recently taking a title at Riyadh last November.
The back-nine starter reeled off three birdies in a row at the first through third holes among her nine for the day.
"I feel like I left actually a good four shots out there," she said. "Like the last I lipped on the left edge. The hole before I left it like an inch short. So I'm looking back thinking I could have done more."
Madsen birdied the par-4 18th to close within a stroke but a lone bogey at the par-4 fifth kept her adrift of Hull.
"Stayed in fairways, so that made it a little easier," Madsen said. "I made a couple good putts and some good, steady birdies."
The 64 was her second-lowest round in an LPGA event.
"It's a pretty scorable course," she said. "There are a lot of birdie chances out there, but the greens are really firm, so that makes it a little trickier.
"It's always great to shoot these really low numbers. I didn't really know where the game was at going into the week. I was feeling sick last week so I couldn't really practice that much, so just great to see a good number today."
Yoon Ina, a 21-year-old LPGA rookie, shared third on 65 with compatriots Im Jin-hee, Lee Mi-hyang and Kim Sei-young plus Taiwan's Chien Peiyun, American Amanda Doherty, Japan's Minami Katsu and Canada's Brooke Henderson.
Yoon eagled the par-5 12th and par-4 18th holes.
"On 12, I got the green by two shots and make a putt like three metres," Yoon said. "And another eagle 18, Second shot was 88 metres and I hit 54-degree and I hit great. I thought I can make birdie, but the gallery was cheering and yelling."