Hannah Green suffered an uncharacteristic fade-out at the Portland Classic today as she continues to prepare for her major championship defence in just more than two weeks' time.

Green, the 23-year-old Australian, led the LPGA tournament in Oregon heading into the back nine today, having started out in the final group two shots back from Mel Reid.

She looked calm and composed and had picked up two shots for the day, while Reid was struggling.

But England's Georgia Hall made a string of birdies to overtake her, and a cluster of bad breaks – including two lip-out putts and a plugged lie in a greenside bunker – saw Green post four bogeys at the final six holes.

Ultimately, she dipped to a tie for 12th at nine-under par, closing with a one-over par 73.

Hall’s withering final-round 68 and South African Ashleigh Buhai’s 65 put them into a playoff, both posting 12-under par, with Hall missing a par putt at the 72nd hole that would have closed it out.

They went two holes of a playoff before Hall got up-and-down from deep rough behind the first green for par and Buhai -- who has never won on the main tour -- chipped to four feet from a similar spot, but pushed her par putt wide.

Green's issues had begun at the par-three 13th hole, with Hall having caught her. Hitting her tee shot on to the right of the green, she three-putted for bogey. Then at the par-three 16th another right-heading tee shot plugged in the bunker and she could not make par there either. Bogeys at 17 and 18 compounded the trouble.

The Perth star won the Portland Classic last year as well as the Women’s PGA Championship. She defends that title in Pennsylvania from October 8.

Portland Classic result