Rising French talent Adela Cernousek conjured an eagle and six birdies in an eight-under-par 64 to break free atop a jammed leaderboard after the first round of the LPGA Portland Classic on Thursday.
After teeing off on 10 and making two birdies in her first 10 holes, Cernousek roared up the leaderboard with birdies at four, five and six.
The 22-year-old carded an eagle at the par-five seventh and added a birdie at the ninth to cap a sensational 64, admitting she let out "a little scream" when she almost holed out for an eagle at the ninth.
"I thought it was going to go in," she said. "I'm super happy to hit the pin because it stayed pretty close and it was cool," she said.
"I felt very good with my whole game," added Cernousek, who turned pro in December after winning a US collegiate golf title playing for Texas A&M last year.
Cernousek was one stroke in front of a group that included former world No 1 Park Sung-hyun and South Korean compatriot Lee5 Jeong-eun, two-time major winner Brooke Henderson of Canada, Chinese rookie Miranda Wang and American Gurleen Kaur.
Henderson and Wang both nabbed seven birdies without a bogey, Henderson teeing off on 10 and launching her round with four straight birdies before adding three more coming in.
Wang had five of her birdies on the back nine, including four in a row at 12, 13, 14 and 15.
Lee5 had an eagle and six birdies with one bogey. Park had eight birdies to offset her lone bogey, as did Kaur.
Five more players were tied on 66 and another eight on five-under 67.
Juli Inkster, the 65-year-old LPGA Hall of Famer making a rare appearance on tour as she preps for the US Women's Senior Open, fired a three-under 69.
"I was a little nervous teeing off," the 31-time LPGA winner admitted. "Settled in pretty good. You know, I actually thought I putted really well today.
"Hit a lot of good irons and I drove the ball well. I was happy with that."