England's Charley Hull shot a three-under 68 for her first 18 hole lead in four years and a one stroke cushion after the opening round of the Volunteers of America Classic tournament on Thursday.
In difficult chilly conditions, Hull rolled in four birdies in a six hole stretch beginning at No. 2 at the Old American Golf Club course in Dallas, Texas.
"I was so cold out there," said Hull, who kept warm by wearing a toque and a red pullover. "I played pretty solid. The golf course is playing so much different than it did last year. It's playing a lot longer, which I prefer.
"I struggled swinging the last two holes, I just got so cold."
Americans Jennifer Kupcho and Jessica Korda and Thailand's Pornanong Phatlum are tied for second at two under.
Hull posted her first birdie of the round on her eighth hole (No 17). This is her first 18 hole lead since the Bahamas LPGA Classic in 2016. She said her swing felt great.
"I felt like I was hitting it really well up until [the eighth hole]. Actually, I didn't hit a green, but I was always just like a club short or something or half a club short and I was still putting just off the green. Then just made some birdies coming in," said Hull.
Five players are tied for fifth at one under, including major champions Anna Nordqvist of Sweden and Brittany Lang.
Defending champion Cheyenne Knight is tied for 10th after a first-round 71.
First round play was suspended for darkness and will resume Friday morning.
Leading first-round scores on Thursday in the LPGA Volunteers of America Championship in Dallas, Texas (play was suspended due to darkness, par-71, USA unless noted):
68 - Charley Hull (ENG)
69 - Jennifer Kupcho, Pornanong Phatlum (THA), Jessica Korda
70 - Gerina Piller, Megan Khang, Anna Nordqvist (SWE), Ally Ewing, Brittany Lang
71 - Cheyenne Knight, Hur Mi-jung (KOR), Ko Jin-young (KOR), Madelene Sagstrom (SWE), Sophia Popov (GER), Lindsey Weaver, Angela Stanford