Australian Hannah Green is in a tie for fourth after shooting a third-round four under at the LPGA Tour's Portland Classic in Oregon.

Currently ranked 19th in the Race to CME Globe Season, Green followed up her 66 and 70 with a 68 at Columbia Edgewater Country Club to sit at 12 under.

The 25-year-old from Perth had four birdies and a bogey on Saturday's first nine, and came home in similar fashion to trail Americans Andrea Lee and Lilia Vu, and Japan's Ayaka Furue by one shot.

"I made a good putt on the third hole - I holed like a 25-footer," Green said.

"All of us played really well on the front nine. That's the scoring nine with two reachable par 5s and a couple of short holes where we have wedges in.

"Got off to a great start and just wanted to hold on on the back nine."

Lee and Vu both reached No.1 in the women's world amateur rankings when they were in college and have a shot at their first LPGA Tour victory.

Vu (69) had four birdies on the back nine while both Lee and Furue, who won the Ladies Scottish Open this year, shot 67s.

Former Women's British Open champion Hinako Shibuno of Japan had a 66 and along with former Women's PGA champion Green, is joined by South Africa's Paula Reto (67) and Daniela Darquea (68) of Ecuador.

"I kind of like that I'm not going to be playing in the last group," Green said.

"You can be aggressive at this golf course but it can also go the wrong way. Just picking your moments where you feel comfortable enough to do so.

"It's a very bunched leaderboard so tomorrow it will be interesting to see whoever comes out on top.

"Hopefully I can shoot a low one because I think six or seven-under is going to be needed."

Fellow Aussies Sarah Kemp (72) is three under and Karis Davisdson (73) two under.

Nelly Korda (69) is six shots behind the leading trio and needs to win to have a chance to return to world No.1.

With AP.