Olivia Mehaffey left herself with an uphill battle to make the cut at the US Open following a disastrous front nine in Houston.
The County Down amateur, who is currently studying at Arizona State University, found herself eight over par after seven holes at the final major of the year.
Mehaffey remained on eight over par with seven holes remaining and will take heart with her closing form as she posted two under par for the final stretch with a run of five pars and two birdies on the 16th and 18th holes.
The 23-year-old ended with a six-over 77 to sit in a share of 125th place and currently sits four shots off the cut mark.
American Amy Olson's bid for her maiden major got off to a solid start as a hole in one and three birdies gave her the first-round lead in Texas.
The 28-year-old started her day on the back nine and raised her arms in triumph after hitting the hole in one on the par-three 16 at Cypress Creek - one of two layouts being used at Champions Golf Course because of reduced daylight.
"I hit a fade to try to hold the wind, and it landed two paces short of the flag, had some good spin on it and just trickled in," said Olson, describing the shot she struck with an eight-iron. "We saw the whole thing, which was fun."
Olson, who tied for second at the 2018 Evian Championship, her best finish in a major, ended the day with a four-under par 67 and a one-shot lead over a packed field that includes nine of the world's top-10 players.
Last year's British Open champion Hinako Shibuno was one shot behind Olson, with a bogey on the par-four 14th the only blemish in three-under par 68 at Cypress Creek, sharing a three-way tie for second with Thailand's Moriya Jutanugarn and South Korean Kim A Lim.
The US Women's Open, which was rescheduled from June due to the Covid-19 pandemic, is celebrating its 75th year and is being held without fans in attendance due to the Covid-19 pandemic.
Twice major winner Brittany Lincicome started strongly with a three birdies but slipped down the leaderboard after a double-bogey on the final hole at Jackrabbit, ending the day on one-under-par.
"I played smart all day, never took a risky chance, always hit it in the middle of the green when I needed to... but obviously that last hole is going to hurt," Lincicome said.
South Korean Lee6 Jeong-eun's title defence got off to a disappointing start as she made three bogeys en route to a 73, while Kim Sei-young, the world number two who won her maiden major title at the Women's PGA Championship in October, carded a 72.