Japan's Hinako Shibuno, the 2019 Women's British Open champion, fired a four-under par 67 to seize a three-stroke lead after Friday's second round of the US Women's Open.
The 22-year-old, who hopes to capture her US Women's Open debut after winning her major debut last year, stood on 7-under 135 after 36 holes at Champions Golf Club in Houston, Texas.
Swedish amateur Linn Grant shot a second 69 to stand second on 138 with Americans Amy Olson, Megan Khang and Kaitlyn Papp another stroke adrift.
Shibuno made six birdies and two bogeys on Jackrabbit, one of two courses used along with Cypress Creek for the opening two rounds, and said she couldn't draw much confidence this week from her major title at Woburn.
"I feel like I'm not really confident at all," Shibuno said through a translator. "It feels like this is not myself."
Rainy and windy conditions had many players feeling off, the December conditions forced because the event was rescheduled from June due to the Covid-19 pandemic, which also prevented spectators from attending.
"I feel strange when I make a birdie and it is totally quiet," Shibuno said.
Shibuno, who won four times last year on the Japan LPGA Tour, opened with a 10-foot birdie putt at the par-5 first, added another at the par-4 sixth and answered her first bogey at the par-4 eighth with birdies at the par-5 10th and par-4 12th.
At the close, she sandwiched birdies at the par-4 15th and 17th around a bogey at the par-3 16th.
"My tee shots found the rough more often, however, my second shots were pretty stable and able to par on to the greens," Shibuno said.
"So my golf today was pretty safe, stable condition. At the same time, when it came to the chance for a birdie, my putting was pretty good."
Grant, 21, had been tied for fourth two years ago at Shoal Creek before rounds of 78 and 81 at the weekend left her sharing 57th.
"I got a bit stressed on the third day going out with the elite group," Grant said. "I'm going to be a little bit more prepared now.
"I feel a little bit more ready. I just try to play as easy as I can, stay inside the pins and on the fairways."
American Cristie Kerr, the 2007 US Women's Open winner, fired a 69 at Cypress Creek to join a sixth-place pack on 140 despite dislocated ribs from a golf cart crash.
"Last night was really bad, really swollen. I yelled at my husband in the middle of the night to bring me another ice bag," she said.
"As the round went on it tightened up. I'm going to get treatment and hopefully feel better in the morning.
"It's painful. I found a way to get it around the first two days and I hope I'm feeling better for the weekend."
World number two Kim Sei-young of South Korea was in a pack sharing 14th on 141 after a 69 at Cypress Creek, where all weekend play will be contested.
World number one Ko Jin-young of South Korea shared 29th on 143 after a 70 at Jackrabbit.
Leading second-round scores on Friday from the 2020 US Women's Open at Champions Golf Club in Houston, Texas (USA unless noted, a-denotes amateur):
135 - Hinako Shibuno (JPN) 68-67
138 - a-Linn Grant (SWE) 69-69
139 - a-Kaitlyn Papp 71-68, Megan Khang 70-69, Amy Olson 67-72
140 - Lindsey Weaver 70-70, Sarah Schmelzel 71-69, Ashleigh Buhai (RSA) 71-69, Cristie Kerr 71-69, Stacy Lewis 72-68, Ariya Jutanugarn (THA) 70-70, Moriya Jutanugarn (THA) 68-72, Yuka Saso (PHI) 69-71
141 - Azahara Munoz (ESP) 71-70, Yealimi Noh 72-69, Lizette Salas 72-69, Lydia Ko (NZL) 71-70, Kim Sei-young (KOR) 72-69, a-Ingrid Lindblad (SWE) 72-69
142 - Lee Min-young2 (KOR) 74-68, Jodi Ewart Shadoff (ENG) 70-72, a-Pauline Roussin-Bouchard (FRA) 70-72, a-Maja Stark (SWE) 70-72, Jenny Shin (KOR) 70-72, Charley Hull (ENG) 69-73, Lee6 Jeong-eun (KOR) 73-69, Jennifer Kupcho 70-72, Kim A-Lim (KOR) 68-74