Yealimi Noh captured her first LPGA title on Sunday, outdueling South Korean Ko Jin-young down the final holes to win the Founders Cup by four strokes.
Noh, a 23-year-old American, fired a three-under-par 68 to finish on 21-under 263 after 72 holes at Florida's Bradenton Country Club.
"This means so much to me," Noh said. "I've worked really hard the past few years and I went through a lot of struggles.
"I really told myself that 2025 is going to be my year so this is the best way to start it."
Three-time Founders Cup winner Ko, a two-time major champion, stumbled with three bogeys in the last six holes to shoot 71 and settle for second on 267 with American Megan Khang third on 268 after firing 68.
Noh's best prior LPGA finishes in six seasons were runner-up efforts in 2019 at Portland and 2020 at the Volunteers of America Classic.
"I've been in contention a couple of times and told myself I could do it but this is the first time I got it done," Noh said. "This is a really big confidence booster for me for the rest of the year."
Noh credited her improved game to a change last year to a broomstick putter.
"Switching to the broomstick helped me so much," Noh said. "I was really struggling with my putting. Switching to the broomstick, that just gave me back my confidence."
Noh birdied the par-4 second and followed with 10 consecutive pars before making back-to-back birdies at 13 and 14.
World number 11 Ko, meanwhile, had grabbed a one-stroke lead with birdies at the fourth and par-5 sixth and eighth holes.
But Ko made bogeys on 13, 14 and 16 to fall four adrift of Noh.
Noh found a greenside bunker at the par-5 17th but saved par and tapped in to par 18 to close the triumph.
Australia's Hannah Green shared fourth on 271 with South Korean Im Jin-hee and Japan's Miyu Yamashita.
Top-ranked Nelly Korda, who won last year here on her hometown course, shared seventh on 272 with France's Celine Boutier and Japan's Minami Katsu.