Leona Maguire closed with a level par 72 to tie for 26th in the Buick LPGA Shanghai.
She made four birdies and two bogeys after opening with a double-bogey six and finished on seven-under-par, 18 shots behind Shanghai native Ruoning Yin.
The Chinese star earned her fourth career victory in dominating fashion at Qizhong Garden Golf Club shattering the 72-hole tournament scoring record that was first set in 2019 by Danielle Kang.
Playing in front of her hometown crowd, Yin teed off in the final group of the day trailing one stroke to 2024 LPGA Tour rookie Mao Saigo.
Yin would be the first to strike recording a birdie on the first hole to knot it up at the top of the leaderboard at 18-under.
Her only other birdie on the front nine came on No. 5 to push herself to the solo-lead at 19-under heading into the turn.
The back nine is when Yin really began to step up her game carding an insurance birdie on the first par-3 of the back, No. 11.
Holes 13-15 were the difference makers with Yin sinking three-straight birdies pushing her lead among the rest of the field even further.
With her fourth victory in sight, Yin all but sealed the deal with back-to-back birdies on the last to holes of the course to get to 25-under 263, her career-best 72-hole score.
“Yeah, so the first day my tee shot wasn’t very good,” Yin said about her performance this week.
“Just I had a call with my coach, Holton Freeman. He’s in LA right now. He fixed my tee shot, so I think this course especially I’m feeling good with my iron shots right now.
“If I can put my ball on the fairway it’s just going to make easier for myself. So I think I just putted really well and my approach shot is pretty good and tee shot is really good. I pieced everything together.”
The third-round leader Saigo had a much different round than Yin.
She recorded just two birdies and a bogey to finish runner-up for the second time this season.
Saigo’s seventh top-10 finish of the season is now tied for the most top-10 finishes in 2024 without a win.
She shares that with Canada’s Brooke Henderson and U.S. Solheim Cup Team member Sarah Schmelzel. Round one’s leader Sei Young Kim began her day three shots back of the leader and did everything she could to help get her back near the top.
She carded six birdies and two bogeys to help her finish tied for second with Saigo and earn her third top-five finish at the Buick LPGA Shanghai and her fourth of the season.
Yealimi Noh had her best finish of the season and lowest since 2021 finishing solo fourth.
The 2021 U.S. Solheim Cup Team member recorded 36-holes of bogey-free golf to bring her total of bogey-free rounds this season to five. Hye-Jin Choi had the round of the day, besting even Yin’s, tying the 18-hole tournament scoring record first set by Kim earlier in the week.
She jumped from T26 to T5, earning her best finish of the season. Yin’s winning partner at the Dow Championship Jeeno Thitikul finished T5 as well.
Defending Champion Angel Yin made a push in the fourth round to become the second player to defend as champion but ran out of holes trying to catch Yin.
She turned in a bogey-free eight birdie performance to finish solo-seventh.