England's Bronte Law is four shots off the pace after battling the heat on day two at the KPMG Women's PGA Championship.
Defending champion Danielle Kang shot her third over-par round of the tournament with a 73 on Sunday, finishing at 2 over for the tournament in a tie for 33rd place.
A week after claiming her first LPGA title at the Walmart NW Arkansas Championship, Hataoka couldn't break through Sunday to join Hisako Higuchi as the only players from Japan to win a women's major, but Hataoka made some history trying at the KPMG Women's PGA Championship.
Park Sung-hyun raised her arms in jubilation and the tears began to fall.
The ball landed two feet from the hole, and Park converted the putt to save par on what could have just as easily ended her hope to win. Park's 69 included a string of nine straight pars at one point.
Ko added further bogeys at the 10th, 17th and 18th to offset just the sole birdie over her back nine, at the par-4 16th.
Park was consistent when it counted and didn't make a single bogey over the last 30 holes of the tournament.
Ever since Sung Hyun Park won the 2017 U.S. Women's Open, she's been waiting to win another major.
Nine strokes behind Ryu entering the day, Hataoka almost pulled off one of the biggest comebacks in LPGA Tour history.
Her up and down from there was undoubtedly critical in her title win as it pilled the pressure on Ryu, who went on to double bogey the next hole.
On her way to posting 67-71-70-74, Henderson was off her game in the closing round. With this major title, Park's early season woes - which saw her miss two cuts in seven starts with one top-10, after not missing any in 23 events a year ago - are well behind her. I just did 100-per cent effort every shot, every putt and still, you know, I like looking at the positive side.
In regulation, Park was trailing Ryu by one stroke at 10-under, when she almost put her second shot into water short of the green.
Park started Sunday's final round trailing Ryu, who built a 3-shot lead surging past Canadian Brooke Henderson and Park on Saturday.
But Ryu birdied the par-3 sixth and par-5 seventh to restore a two-stroke edge at 11-under.
"I think I had a bit of confidence coming into this week because of the two top-10 finishes these couple weeks, and I felt like I was driving it pretty good and rolling it good", Ko said.
"Up and down all day", she said of a round that included five birdies and four bogeys.