LOS ANGELES (AFP) - Hannah Green became the first Australian to win a Major championship in 13 years on Sunday (June 23), holding off a pack of marquee players to deliver wire-to-wire victory at the Women's PGA Championship.

The 22-year-old, who had never won on the LPGA Tour before, had an up and down par save on the final hole for an even-par 72 and a one-stroke victory over defending champion Park Sung Hyun.

"To win a Major as my first event I am so over the moon," said Green.

The Perth native capped her win with a nerve-wracking four-foot putt on the 18th for her third birdie of the round to reach a nine-under 279 total at the Hazeltine National Golf Club in Chaska, Minnesota.

"I was really nervous playing the last five holes," said Green. "I am just happy I made a clutch putt because that is what I was struggling with in the middle of the round. It really is surreal."

Green had to overcome a mid-round wobble with three bogeys in a four-hole stretch. But then she got back on track with a long birdie putt on the 16th to become the first player to win the event wire-to-wire since Taiwan's Tseng Yani in 2011.

Green said she tried not to let the magnitude of the moment distract her from her goal.

"I didn't feel too nervous at the start, but coming towards the back nine and missing putts on eight and nine, that really hurt. I wasn't in the right head space for that," Green said.

"Then making the putt on 16 obviously relieves everything. I heard Sung Hyun birdied the last so I knew I needed to make par. I really didn't want to play that hole again. I am just really happy I made it."

She is the third woman from Australia to win a Major, joining seven-time winner Karrie Webb and three-time winner Jan Stephenson, who won the 1982 PGA Championship.

Green got some added inspiration when she walked off the eighth green on Sunday when a young fan named Lily stepped forward and handed her a poem she had written.

"I got a cute little poem saying that I had given her a ball and also said, 'You can win this'," Green said.

"I had it in the back of my yardage book because I didn't want it to get rained on. I didn't want it to get wet and ruined.

"A couple times on the back nine when I was feeling nervous and had some time, I actually read it to myself. I have to thank Lily for writing that. I think it really helped me."

Green had a one-shot lead going into the final round as she sat on a 54-hole lead for the first time in her career with no less than four Major champions within striking distance, comprising Park, Ariya Jutanugarn, Park Inbee and Danielle Kang.

Green started her tournament with luck and momentum on her side as she holed putts in each of the first two rounds to take a three-shot lead into the weekend.

"I felt like Justin Rose on the first day - barely hitting any greens and holing a lot of putts," said Green, who missed the cut last week and came into this event ranked 141st in the world.

Park Sung Hyun, who sank an 18-foot birdie putt at the final hole to get to eight-under overall and put added pressure on Green's finish, fired a four-under 68. She was the lone player to post four sub-par rounds this week.

Park birdied the second playoff hole to defeat Ryu So Yeon last year and she almost sent the event into its fourth playoff in the past six years.

England's Mel Reid shot a six-under 66 to finish in a tie for third with American Nelly Korda (71) on six-under 282.

Kang, who won this event two years ago, hit a 70 to finish in a tie for fifth with fellow American Lizette Salas (72), at five-under 283.