Park Sung-hyun won the KPMG Women’s PGA Championship following the first three-way play-off in the tournament’s 63-year history.
The South Korean edged out compatriot Ryu So-yeon and Japan’s Nasa Hataoka in a dramatic finale after the trio finished tied on 10 under par in Illinois.
Ryu and Park each birdied the first additional hole, eliminating 19-year-old Hataoka, before play was suspended for 20 minutes due to severe weather.
Park then held her nerve to win her second major in as many years, sinking a birdie on the second play-off hole after Ryu could only manage par.
“It was a really long round today and I still can’t believe I’m sitting next to this trophy,” said champion Park, according to the LPGA Twitter account.
“It’s been a tough year for me since I’ve missed five cuts but that said I feel like I played really well this week and I’m proud of myself.
“I got less nervous during the play-off. My caddie and I were joking around and it made me more comfortable. This trophy gives me a lot of confidence.”
Overnight leader Ryu, who began the day three shots ahead, appeared on course to take the title at Kemper Lakes Golf Club before a tee shot into water led to an untimely double bogey on the 17th hole which handed lifelines to Park and Hataoka.
The mistake meant the 28-year-old finished the round one over, while eventual winner Park, who started the day third, was three under.
Runner-up Ryu said: “I played my best and that’s all I can ask for. Hopefully I will win this tournament one day soon.
“Sung Hyun (Park) and I both did out best, and in the end she won this one.”
Hataoka, who won her first LPGA title with victory at the NW Arkansas Championship six days ago, enjoyed a remarkable round on Sunday, hitting five birdies and two eagles to register an eight-under 64 and claw back a nine-shot deficit on the lead.
She was in the clubhouse while 24-year-old Park and Ryu completed their rounds and was quickly eliminated after returning for the tense play-off.
Americans Angel Yin and Jessica Korda, on seven under, finished tied for fourth.
England’s Charley Hull was a shot behind following a final-round 67, sharing sixth place with Canada’s Brooke Henderson, who began the day second but carded a two-over 74.
Park’s success follows her win at last year’s US Women’s Open.