After the round, Jutanugarn was consoled by younger sister Ariya, who won her first major championship past year.
Sweden's Anna Nordqvist came from five shots behind 36 hole leader Moriya Jutaungarn to win in a playoff against American Brittany Altomare who had begun the final round tied with the eventual victor.
But with the final hole bogey, she dropped to eight under par, one shot behind Brittany Altomare and Anna Nordqvist.
The 2009 LPGA Championship victor, who battled glandular fever (mononucleosis) this summer, outlasted third-year-pro Altomare under borderline-unplayable conditions similar to those on Thursday that forced the LPGA to reduce the tourney to 54 holes.
British Open victor Kim In-kyung is in joint fourth along with world number one Lydia Ko and US Open victor Park Sung-hyun, with the trio three shots adrift of Jutanugarn.
In the second round, Aditi had four bogeys and a double in conditions that have been tough through the week and the event reduced to 54 holes.
Ko finished one shot back, with her third placing her best finish in a major in her last six attempts, and marking her eighth finish of third-or-better in a major championship. A recent 3rd place finish at the event in Portland suggested her game was improving but if she had gone on to win it would have been one of the biggest upsets for some time on the LPGA Tour.
It capped a bittersweet tournament for the former world No.1, who has endured a testing year but played with aplomb at a tournament she won two years ago.
This was the fifth and last major tournament of the 2017 LPGA season.
Lydia Ko, the 2015 victor, also made five at the final hole to miss out on the play-off and finish tied third alongside Jutanugarn and Katherine Kirk.
Jutanugarn had chances to match her 65 from Friday's first round though let birdie chances slip after consistently accurate approach shots. It was there that Nordqvist continued her charge, having already picked up three birdies and an eagle to offset the two bogeys with which she had to start the day. The 30-year old hasn't played much golf this year after getting hit with a brutal bout of mononucleosis at the beginning of the season.
But then the 20-year-old Korean born New Zealander missed a short putt for par at the 18 hole to finish one-stroke outside the play-off.
"I played great today and hopefully I can keep it going", said the 33 year-old.
Perth's Minjee Lee and Queenslander Sarah Jane Smith each closed with a 75 to finish one over and three over, respectively.