On the first playoff hole, Ryu drained a 20-footer for birdie and Park responded to extend with a 15-footer. But once Ryu made a double bogey on the 17th hole by hitting her tee shot into the hazard, she allowed Park and Hataoka to share the lead, forcing a sudden-death playoff.
The 24 year old who earned the LPGA's Rookie of the Year award in 2017 after winning the U.S. Women's Open, defeated two rivals in a playoff to capture the KPMG Women's PGA Championship at Kemper Lakes Sunday.
South Korea's Park Sung Hyun was 7 under after a 71, and American Angel Yin had a 68 to get to 6 under.
Indian golfer Aditi Ashok capped a disappointing week with a one-over 73 for a total of nine-over 297 to finish Tied-63rd at the KPMG Women's PGA Championships here.
Nine strokes behind Ryu entering the day, Hataoka almost pulled off one of the biggest comebacks in LPGA Tour history. "Hopefully tomorrow I can just go out and put a good score together and just kind of see what happens", said Henderson, who will play in a group on Sunday with Ryu and Park.
But that lead disappeared on the very next hole, the par-3 17th, where Ryu found water off the tee.
She seemed pretty comfortable on a day when the temperature hit the low 90s.
But unsafe halted play as Park and Ryu battled for silverware, the latter having blown her overnight lead with a one-over 73. She made double bogey and dropped back into a three-way tie.
But Henderson's putter grew cold over the closing stretch and missed a series of birdie and par putts.
The back-to-back birdies by Ryu and two late bogeys by Henderson turned things in a hurry. She shot a 5-under 67 on another scorching afternoon to get to 11-under 205 and move closer to her third major victory.
Heading into Sunday's final round of the Women's PGA Championship four shots off the lead, the South Korean eventually emerged from a playoff with a second major title.
In a span of three holes on the back nine on Saturday she went from trailing Henderson by two to leading by two strokes. She followed that with a neat one on the par-4 No. 12, when her shot from the rough bounced off the stick and into the cup.
Hataoka, still a teenager at 19, has a victory and two second-place finishes in her last six starts, six top-10 finishes in her last seven starts.