Green snatches Women's World Championship with last-gasp birdie
The US LPGA Tour's flagship event in Asia had looked like it was heading for a playoff after Boutier's five-under 67 put her in the clubhouse at 12-under par and for Green to draw level with birdies at the 16th and 17th.
But the Australian completed a hat-trick of birdies over the closing holes to snatch victory when her snaking putt on the 18th green curled into the cup to a huge ovation.
"I knew I needed to at least birdie the last to win by one," said world number 29 Green, who was drenched in champagne by her fellow Australian competitors in celebration after finishing the tournament on 13-under 275.
"As soon as that putt went in, I was like, 'Oh, my God, I've won!'," said the 27-year-old, who lifted her fourth LPGA Tour title.
"You have to take these highs when they come because it doesn't always come and golf can be a learning sport sometimes.
"Celine played great today but she didn't end up with the trophy in her hands. But she should still be proud of how she performed under this pressure," said Green.
It was the Australian's first win in Asia and also eased the heartbreak of finishing second in Singapore three years ago.
"I almost won the championship in 2021 when I was playing it for the first time," said Green.
"I remembered I three-putted 17 and then three-putted again on 18 to lose. It feels great to have this trophy in my hands now."
'It was frustrating'
Playing in the group ahead of Green on the Tanjong course at Sentosa Golf Club, Boutier was unable to make a birdie over her closing holes to put pressure on the Australian and missed a great chance on 17.
"I knew my putt (on 17) was going to be important but it ended up being short-sided. It was frustrating," said world number three Boutier.
"I gave myself chances. I made some putts and also missed some. But such things happen and I can't be too mad about my round today."
Ko Jin-young of South Korea, who was defending her 2022 and 2023 titles, briefly threatened to get into the mix when she drained a monster 90-foot birdie putt at the 11th.
But two bogeys followed and her one-under 71 saw her finish six shots behind Green on seven-under 281.
Japan's Ayaka Furue took a two-shot lead into the final round Sunday but had a day to forget, completing a three-over card of 75 with a scruffy double bogey at the 18th to finish six behind playing partner Green.
World number one Lilia Vu, who started the day five shots back of the lead, withdrew during her final round because of illness.