It took until her last shot to hit the front, but Hannah Green didn't care one bit.

Green overcame a three-shot deficit today to win the Cambia Portland Classic, over-running first-year pro Yealimi Noh in a dramatic finish at the Columbia Edgewater Country Club.

Green, who set consecutive personal best LPGA Tour scores on day one and two to set up the tournament, had begun the final day three behind Noh after a lapse in third round.

Birdies on the third, fifth and seventh holes enabled her to close within a shot of the Californian, but a bogey on the 11th and Noh's birdie on the 14th reinstated the margin with just four holes to play.

But when it mattered most, the West Australian found an extra gear.

Her birdie from 5m on the 15th turned the screws on Noh, who made bogey on the short 16th.

Green, who putted well all week, then made the critical move when she canned a curling, downhill 6m birdie on the 17th to draw level.

Noh found the bunker off the last tee, blew her second through the green and then left herself a 4m par try after knocking her chip long.

Green left her lag putt from the fringe well short, but was given a reprieve when her opponent's putt for four slid by.

The Mount Lawley member calmly stood over a similar length putt to the one that she made to win the KPMG PGA Championship in June and made a perfect stroke for her second title in just over two months.

"What I did really well coming down the stretch was giving myself opportunities for birdies," an elated Green said.

"I think the putt on 17 was obviously huge to get to a tie with Yealimi coming into the last and then the clutch putt on the last was something I'll remember for a long time."

Green became the fifth multiple winner of the 2019 LPGA Tour season, joining Jin Young Ko (4), Brooke Henderson (2), Sei Young Kim (2) and Sung Hyun Park (2).

She is the ninth Australian player to win multiple LPGA Tour events and the first Aussie to do so since fellow West Australian Minjee Lee in 2016

It vaulted her all the way to No.12 in the tour's CME Race to the Globe standings and on the verge of the world's top 20 when rankings are updated tomorrow.

Green, ever modest, said she didn't want to get ahead of herself, but was happy to show her major championship breakthrough wasn't a fluke.

"I was surprised at KPMG and again this week with my two low scores, so I don't want to get cocky, but I also don't want to sell myself short and get myself in these positions a bit more," she said.

"I was actually really confident with the (last) putt, there wasn't too much break, it was downhill, but a similar situation to before (at the KPMG).

"I remember that experience, and earlier this week being confident over it ... and once I hit it, I knew it was going in.

"I don't normally fist pump, but back-to-back on 17 and 18 I did because I knew it was obviously huge.

"It was a bit different reaction to KPMG, a bit more happy than emotional, but yeah, it was really cool."

LEADERBOARD