Park had just one bogey in a 5-under 67 for the best score of Thursday’s morning groups. Caroline Hedwall of Sweden was a shot back, with six players at 2 under.
Concerned about bad weather, tournament officials moved up the tees, and with the rain holding off, Park was able to play aggressively.
“I never had practiced from those tees, so I was a little bit shocked when I went to the tees,” Park said.
Not that she was complaining.
She repeatedly gave herself short putts, and the way she has excelled in her short game lately, Park cruised to a low score.
“So instead of hitting like 5-irons, we were hitting 9-irons, and that was making the course much easier,” she said. “I was actually able to go for some pins and give myself a lot of opportunities today. I made a lot of putts and didn’t leave much out there.”
No player has won the first three majors in a season with at least four majors. The 2008 U.S. Women’s Open champion, Park has already won five times this year, including her last two tournaments.
Starting on No. 10, Park birdied her first hole, then started racking up pars. She made the turn at 2 under before birdies on three of her next four holes.
At 5 under, Park briefly struggled with her tee shots, needing to save par on Nos. 5 and 7. On No. 6, her 15th hole of the day, she had to lay up out of the tall grass and settled for her lone bogey.
Park got herself back to 5 under on the par-5 No. 8 with a chip shot to about 5 feet for an easy birdie putt.
Hedwall was at 5 under heading into her final hole, No. 9. But she hit over the green into the rough, then just missed her par putt to finish with a 4-under 68.