Maja Stark fired three birdies in an impressively steady two-under-par 70 at unforgiving Erin Hills on Saturday to seize a one stroke lead over Julia Lopez Ramirez heading into the final round of the 80th US Women's Open.
Sweden's Stark, a European Solheim Cup stalwart chasing her first major title, kept her focus in a round that stretched nearly six hours as players wrestled with firm, fast greens on a breezy, sunny day in Wisconsin.
Her seven-under-par total of 209 put her one stroke clear of Spanish qualifier Lopez Ramirez, whose four-under-par 68 was the best score of a day on which only nine players broke par.
Japan's Mai Saigo, who started the day with a three-shot lead, carded a three-over-par 75 to share third alongside compatriots Rio Takeda and Hinako Shibuno on five-under 211.
World No 1 Nelly Korda, who played alongside Saigo in the final group, finished strong in a one-over 73 that left her three adrift on four-under 212.
Stark said the very difficulty of the course actually made her less anxious – a key for her as she tries to kick the habit of "playing scared".
"In normal tournaments, I kind of swing scared because I think it's a birdie competition, but here it's really not," Stark said, adding that on Sunday she'll just "try to play freely".
Stark opened with a confidence-boosting birdie at the first hole. She bogeyed the third, but stuck her second shot at the 10th two feet from the pin for a birdie.
Stark rattled in a 21-foot birdie at the par-three 16th to seize a share of the lead on seven-under, capping her round with a par at the par-five 18th and emerging with the solo lead as Saigo closed with back-to-back bogeys.
The tough scoring made Lopez Ramirez's round look all the more impressive.
The 22-year-old, who had to pause her LPGA rookie campaign in March after undergoing an appendectomy, eagled the par-five first and bounced back frm a bogey at the third with a birdie at th seventh, where she got up and down from a greenside bunker.
She added birdies at 12 and 16 to put herself in contention for a first major title.
"It was just mentally a strong day for me, keeping myself present and dealing with what's in front of me," Lopez Ramirez added.
Saigo, gunning for a second major title of the season after winning the Chevron Championship in April, was battling even before her bogey-bogey finish.
She had two birdies and a bogey in her first three holes then bogeyed the fourth, fifth and sixth – failing to get up and down after missing the geen at all three.
KORDA RALLIES
The 23-year-old had regained the solo lead with an eight-foot birdie at the 12th but couldn't hang on.
Takeda joined her on five-under with a two-under par 70 highlighted by a six-foot eagle at the first. Former British Open champion Shibuno had two birdies and two bogeys in her even par 72.
Korda appeared to be spiraling out of contention with four bogeys on the front nine. That included three-putts at the second and fifth and a five-foot miss at the seventh.
But the American star clawed back with birdies at the 14th and 15th – where she took advantage of the US Golf Association's decision to move up the tee to drive the green and calmly rolled in an eight-foot birdie putt.
Her six-foot birdie putt at the 18th circled the cup before falling in, leaving her exactly where she started the day three shots off the lead.
"I was happy to kind of rally back on the back nine after having such a poor start," Korda said. "It's all about being patient. There's just so many ups and downs and you just have to kind of stick with it .... it just takes one shot."