Hannah Green brought a sense of déjà vu today as she dominated the opening round of the Portland Classic on the LPGA Tour.

The Australian won this tournament last year and her first-ever title defence on the big tour began with a bang.

Green, 23, rammed home seven birdies in an opening 66 that put her into a share of the lead in the tournament, reduced to 54 holes because of concerns over the air quality in Portland, Oregon after wildfires in the area.

Not even a weather delay could halt the momentum she took from four birdies in the first five holes. An hour later she came back firing again, hitting a gorgeous short iron shot over the flag at the par-three 13th that spun back to tap-in range.

Initially joining the early leader Cydney Clanton of the United States at six-under, then bombing a long, curling birdie putt at the 16th hole to go to the outright lead before an untimely bogey at the 18th hole in near-darkness brought that pair back together at six-under.

Earlier she’d made a brilliant par-save after going bunker-to-bunker on the par-four 15th.

It all came together beautifully for a player who is only a fortnight away from defending her first major championship, the Women’s PGA. "I mean, I didn't finish well. I did bogey my last hole, but obviously did some great things out there," she said later. "Putted really well, so I need to continue that. I'm kind of glad that I have a quick turnover. Hopefully I can continue the momentum tomorrow."

Green was not the only Australian to fire early at Columbia Edgewater Country Club. Fellow-West Aussie Minjee Lee also played nicely on her way to an opening 70 although bogeys at the last two holes would have left her with a sour taste.

Amateur Gabriela Ruffels also went under par with a 71, playing on invitation.

Portland Classic leaderboard