Amy Yang led by two shots in the final round of the Women's PGA Championship, but Charley Hull's challenge was thwarted by a triple bogey late in the match.
The South Korean player, who is chasing her first major victory at Sahalie Country Club in Washington state, shot a 71 in the third round.
American Lauren Hartlage shot 69 to tie for second with Japan's Miyu Yamashita, while the overnight co-leader was one shot back at 74.
Women's Open champion Lilia Vu had the best score of the day with a 68 to be grouped with the three-under group, four shots behind the leader. The group also included Lexi Thompson, who is pursuing a major championship after announcing her retirement from full-time golf at the end of the season.
Britain's Hull made three consecutive birdies at the start of the back nine to move within two shots of the lead, but on the par-3 17th hole, she hit water on her tee shot and shot six, dropping to a tie for 12th, six shots behind the leader.
Charlie Hull suffered a nightmare triple bogey on the 17th hole at Sahali Country Club and fell six shots behind
“My buddy asked me yesterday, 'What happened to you on the 17th hole yesterday? You almost fell in the water,'” said Hull, who has been battling a knee injury.
“When I was standing on the tee, I thought to myself, I almost missed it. Then I thought about the water and I hit it right into it. It's human nature.
“That's not like me. I played well today, didn't do anything wrong and played well when I needed to. But I still feel confident going into tomorrow's match. Anything can happen.”
Amy Young leads by two shots heading into Sunday's final round
Young, 34, made just three bogeys in 54 holes as she looks to add a major championship to her five LPGA Tour victories.
“I grew up watching a lot of great players play, and I saw them win all the major tournaments,” she said. “Because of them, I dreamed of playing here. I worked hard for this.”
“It means a lot, but we still have 18 holes to play and a lot of golf left to play in the majors.”
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