Former world number one Stacy Lewis birdied the first extra hole to win the ASI Ladies Scottish Open in a four-way play-off at the Renaissance Club.
Lewis holed from 18 feet to secure the 13th LPGA title of her career after finishing tied on five under par with compatriot Cheyenne Knight, Spain's Azahara Munoz and Denmark's Emily Pedersen.
Munoz and Pedersen were unable to make unlikely birdies from long range and Knight missed her birdie attempt from 15 feet to keep the play-off going.
Ireland's Leona Maguire finished in a tie for 18th on one over after the Cavan native carded a final round 70 - her best round across the four days - to move up the leaderboard.
Lewis, who won the 2013 Women's British Open at St Andrews, began the day a shot behind Munoz but made the ideal start with birdies on the second and third after Munoz had three-putted the opening hole.
Munoz looked to be out of contention as she double bogeyed the sixth and dropped another shot on the ninth to be out in 40, but Lewis pitched into a bunker on the 11th to make her own double bogey as all the contenders began to struggle.
Three birdies in the first seven holes had given American Jennifer Song the lead on eight under par, but she played her last 10 in five over to miss out on the play-off by two shots.
Pedersen was first to set the clubhouse target after a closing 68 and was soon joined by Knight, with Munoz bravely saving par on the 18th from 10 feet after Lewis had never threatened to hole a long birdie attempt to win in regulation.
"I was pretty in control there through 10 holes and then one funky swing on 11 brought everybody back into it and then it was just up and down, a roller coaster those last three holes," a relieved Lewis said.
"I had a chance on 16 to make birdie and didn't, I had that putt on 17 I thought I made. Felt fortunate to get in the play-off and then hit a great second shot there that set up that putt."
Lewis had been frustrated by the pace of play on Saturday and admitted it was a similar story in the final round, but added: "A little bit, but I did a better job of (dealing with) it.
"I told my caddie on the second hole that I cannot make one comment today about the pace of play so I tried to not think about it, just stick to my game and did it all day other than a couple of golf swings."
Overnight leader Munoz, who carded a final round of 73, said: "I'm proud of myself. Obviously it was a tough day and I didn't have a good start.
"I got pretty unlucky on number six. I got a plugged lie in the bunker so I had to take an unplayable. But I fought really hard. I made some really nice putts coming in and that's all you can do."