It was Green's first victory on the LPGA Tour and she becomes the first Australian woman since Karrie Webb (Kraft Nabisco 2006) to win a major.

Green held her nerve and saved par from the bunker with a five-foot putt on the final hole after Park drained an 18-foot birdie putt on the 18th hole to bring added pressure.

Among those who celebrated with Green was Webb, who brought Green to America four years ago as part of her scholarship program.

Green, in only her second full year on the LPGA Tour, is the first wire-to-wire winner of this major since 2011.

"I'm pretty much speechless," Green said. "I was really nervous the last five holes and just really – I made a clutch putt and that was kind of got me through another one.

"To make the one on the last is really is surreal. Obviously I heard Sung made the last one, knew I needed to make par.

"Didn't want to play that hole again (playoff). I'm really happy I made it."

RIGHT: Green was in tears after winning the Women’s PGA Championship. PHOTO: Jamie Squire/Getty Images.

She said it was a dream to win in front of friends.

"It's awesome. I've always wanted to win in front of an Aussie crowd.

"I felt even that's what it was like today. Anything to just be winning in majors the first event."

Green built a handy lead in the final round before all but frittering it away with three bogeys in a four-hole stretch around the turn.

She steadied the ship after that and a 15-foot birdie at the 16th hole proved decisive.

American Nelly Korda (71) and England's Mel Reid (66) tied for third, three shots behind.

Thailand's Ariya Jutanugarn, who started the day one shot behind Green, had a nightmare 77 to plunge into a tie for 10th on three-under.

Minjee Lee shot a final round one-under 71 to tie for 30th while Victorian Su Oh finished six over for tied 53rd.