Mi Jung Hur carded a five-under-par 66 to take a one-shot lead at the Volunteers of America Texas Shootout on Thursday.
Hur is closely followed by Gerina Piller, Eun-Hee Ji and So Yeon Ryu, who all sit in a tie for second after firing four-under-par 67s.
Jenny Shin, Sei Young Kim, Amy Yang and Catriona Matthew are two strokes off the lead in a tie for fifth.
World number three Lexi Thompson struggled as she recorded a four-over-par 75, while defending champion Inbee Park skipped the event as she is recovering from a thumb injury.
Hur, who finished in a season-high tie for sixth at the Swinging Skirts LPGA Classic last week, was in sensational form on her front nine as she made four consecutive birdies from the 15th to 18th. The South Korean looked on track to continue her excellent run of form on her back nine as she began with a birdie at the first, but she committed her lone blunder of the round at the fifth, where she registered a bogey.
She did atone for her mistake, though, as she made her sixth birdie of the round at the eighth, which also gave her the outright lead.
Piller, who has finished in the top 10 in her last three events – the Kia Classic, ANA Inspiration and Swinging Skirts LPGA Classic – began her campaign on a quiet note as she made a lone birdie on her front nine.
It was a whole different story on the back nine, though, as she began with a bogey at the first before making her charge with four birdies in the space of her next seven holes.
Ji kicked off her round with a trio of birdies on the front nine before making consecutive birdies at the 11th and 12th. She would have joined Hur at the summit of the leaderboard had she not stumbled at the final hole, where she recorded a bogey.
Ryu was in great form on Thursday as she made a duo of birdies on the front nine to get off to a solid start. The 25-year-old continued to impress on the back as she made two more birdies to complete a bogey-free round.
Thompson had a day to forget as she made one birdie, three bogeys and a double bogey at the par-four ninth during her round of 75.
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