Australian Minjee Lee and American Mina Harigae are tied for the lead at nine under after two rounds of the U.S. Women's Open played at Pine Needles.

Harigae was tied for the lead after Thursday's first round, and followed it up her 64 with a solid 69, while Lee posted a 67 on Thursday and then followed it with Friday's second-best round of the day, shooting a 66.

The actual round of the day went to South Korea's Choi Hye-jin, who shot a seven-under 64 after entering the day at even par to sit in a tie for third heading into the weekend.

She is tied two shots back from the lead at seven under with Sweden's Anna Nordqvist, one shot ahead of fellow Swede, amateur Ingrid Lindblad, who posted a one under score on Friday after setting the U.S. Women's Open record for lowest score by an amateur with her opening round 65.

Lindblad is tied with world number one Ko Jin-young at six under, with South Korea's Kim Sei-young and Thailand's Moriya Jatanugarn one stroke back at five under.

Rounding out the top-10 are the American trio of Ryann O'Toole, Megan Khang and Andrea Lee, along with England's Bronte Law and South Korea's Park Sung-hyun, tied for ninth at four under.

American Mina Harigae is the outright leader after the first round of the U.S. Women's Open with a seven-under 64, but she was arguably outshone by Swedish amateur Ingrid Lindblad.

Harigae had nine birdies with two bogeys – becoming the sixth player to shoot 64 in tournament history – but leads by just one stroke from Lindblad, who shot the best score by an amateur in U.S. Women's Open history with her 65.

Lindblad was spectacular, particularly on the front-nine, where she birdied the first three holes, as well as the eigthth and ninth, before finally registering her only bogey of the round on the 10th. She responded to that adversity in fine fashion, collecting birdies on 12 and 13.

The chasing pack sits two back from Lindblad, with Swedish compatriot Anna Nordqvist tied at four under with Australia's Minjee Lee and America's Ryann O'Toole.

Keeping with the Swedish theme, Lindblad was partnered with legendary three-time U.S. Women's Open champion Annika Sorenstam, who gave the 22-year-old some glowing praise after their round.

"She's authentic," she said. "She's got a special look, but she's a fearless player.

"She's confident in her own game. I know she doesn't shy away from the limelight that maybe I did as a young girl."

American duo Lexi Thompson and Ally Ewing are tied for sixth at three under, and there is an 11-woman logjam sitting inside the top-10, tied for eighth at two under.