Sorenstam, of Sweden, a three-time U.S. Women’s Open champion, turned 50 last October and seemed ordained to step into the lead of this championship.

The World Golf Hall of Famer birdied her first and last holes of the day in delivering a six-birdie, one-bogey effort that fell one stroke short of the 18-hole record for the fledgling championship, 66s by Laura Davies in 2018 at Chicago Golf Club and by Trish Johnson in 2019 at Pine Needles Lodge & Golf Club.

“I love the golf course,” said Sorenstam, who played her last U.S. Women’s Open in 2008. “I was very happy how I played today. This course can be quite tricky around the greens. I realize I had a few slippery ones, but it was nice to finish on a high note.”

That Ebster, 51, joined Sorenstam at the top was quite unexpected. The part-time instructor and junior college assistant coach “was pulling out carts at 6 a.m.” in the days before she travelled to the championship.

“I’m so thankful for my club back home, Turlock Golf and Country Club,” said Ebster, who competed against two-time USGA champion Pat Hurst while growing up in Northern California. “They raised money for me to get here. I’m just the little club pro who came out, and so I’m super-excited.”

Ebster joined Sorenstam at 5-under in dramatic fashion, with an eagle on her final hole of the day, the 513-yard, par-5 11th, holing out a 115-yard shot with a 9-iron. Afterward, Ebster stood at the interview podium and tried to assess her lofty position in the 120-player field that includes 11 past U.S. Women’s Open champions.

“OMG – that’s all I got to say, OMG,” said Ebster, who has run the junior golf program at Turlock for three years and got into the field as the first alternate from the Woodburn, Oregon, qualifying site.

“I play every Friday with my ladies’ group, and then between lessons I’ll get out and hit a few shots and practice chipping and putting. But, you know, I really don’t get a lot of time to practice.”

Sorenstam and Ebster have a two-stroke cushion on the 60 players in the morning wave who completed their rounds, with Kris Tschetter (the runner-up to Sorenstam in the 1996 U.S. Women’s Open) posting a 3-under 69, and 1988 U.S. Women’s Open champion Liselotte Neumann, of Sweden, at 2-under 70. Laura Davies, of England, who won the inaugural U.S. Senior Women’s Open at Chicago Golf Club in 2018, was in a quartet of players at 1-under 71 with 1984 U.S. Women’s Open runner-up Rosie Jones, 2021 Solheim Cup captain Catriona Matthew of Scotland and seven-time USGA champion Ellen Port.

Play was halted by rain at 3:53 p.m., and it was suspended for the day at 5:15 p.m., with the afternoon wave roughly halfway through the round. The course absorbed about an inch of rain.