In short:

Australian golfer Grace Kim has had seven birdies and an eagle for an opening round of 66 at the LPGA's Portland Classic.

Kim's 6-under round put her joint second, one shot back from leader Mariel Galdiano of Colombia.

Fellow Australian Robyn Choi is one shot back, tied for ninth, while Steph Kyriacou will need a solid second round to make the cut after an opening level par round.

Australian golfer Grace Kim has continued her hot run with a stellar opening round at the LPGA Tour's Portland Classic.

Fresh off two straight top-10 finishes, Kim is just one stroke behind Colombian leader Mariel Galdiano after the first round at the Columbia-Edgewater Country Club.

Playing an all-out attack, the major champion collected seven birdies and an eagle to finish the day in a seven-way tie for second.

The world number 38 also needed only 24 putts, the fewest of any player in the field.

Kim started with a three-birdie stretch after starting her round on the 10th hole.

"Having that three-birdie start is just a nice feeling to kick-start things," the 25-year-old said.

"A lot of us out here are pretty straight, fairways and greens.

"But in terms of holing all those putts, knowing that the greens roll quite true … it's really nice to just put a stroke on it and see where it would normally go."

Kim is in a batch at 6-under, including Augusta National women's amateur champion Maria Jose Marin, Arpichaya Yubol and Olivia Cowan.

The 20-year-old Marin landed five-straight birdies on the front nine.

"I reached a flow state that I haven't reached in a while," she said.

"After the British Open I didn't play my best golf, and I think getting that confidence back with this round is all that I needed."

One shot behind them and tied for ninth is Australian Robyn Choi (67), who sprang to life on the back nine.

After going out in even par with a birdie and bogey, Choi stormed home with four consecutive birdies beginning on the 12th. She then added another on the 17th to rocket up the field.

Fellow Australian Steph Kyriacou (72) had a solid round of even par, but will have to play well with the cut projected to be around 1-under.

American pacesetter Galdiano's opening 65 featured nine birdies.

Galdiano, a 28-year-old from Hawaii, is making her fourth LPGA Tour start of the year.

"Every start on the LPGA means a lot to me, so just enjoy the moment, really," she said.

AAP