Yin, 23, endured a rollercoaster round before carding a closing two-under-par 70 to finish the tournament at 14 under.

The 2023 Women's PGA Championship winner rattled in five birdies and three bogeys on her way to victory at TPC Boston, in Norton, Massachusetts.

Yin finished with a crucial birdie four on the par-five 18th to complete her first win on the tour since 2024.

"I was really emotional when I was on the 18th green and just felt like all the hard work paid off," Yin said afterwards. "Just really happy how I grinded out there today."

Yin admitted she had been nervously looking over her shoulder at playing partners Kim Hyo-joo and Kim Sei-young down the stretch.

Kim Hyo-joo shot a one-under-par 71 to finish on 12 under, while Kim Sei-young carded a one-over-par 73 to tie with Rose Zhange for fourth place, one back from Allisen Corpuz of the United States on 11 under.

"I felt like that was the longest 18th hole I've ever played - because they're just so good and they don't really make mistakes," Yin said.

Yin said she had doubted whether she would ever win another title after a frustrating sequence of near-misses this season and last year.

"I've had quite a few times where I was really close but just keep missing by one or two," she said. "I was always harsh on myself...I doubted if I can win on this tour again.

"I was not a happy person last year; but this year I think I learn a lot. The biggest thing I learn is that life comes from you, not at you. And that good things take time and just be patient about it."