Caroline Masson fired a 7-under 64 on Thursday to grab a 2-stroke lead after the opening round of the inaugural North Texas LPGA Shootout.
Masson carded her best-ever score on the LPGA Tour. The rookie had missed the cut in four of her five starts this year.
Carlota Ciganda is alone in second place at minus-5 at Las Colinas Country Club.
Women's world No. 1 Inbee Park posted a 4-under 67. She is tied for third place with Mo Martin, Kristy McPherson, Mi Jung Hur and Felicity Johnson.
Amateur Taylor Coleman stands alongside Hee Young Park and Christina Kim in eighth place at 3-under 68.
Masson played the back nine first on Thursday and got going with a birdie on his opening hole. She came back three holes later with another birdie at the 13th.
The German, who played one year on the Oklahoma State women's golf team, parred four in row from the 14th before dropping in her third birdie of the day at the 18th.
Masson started her second nine with a trio of pars. She moved to 4-under with a birdie at the fourth. The 23-year-old birdied three of the next four holes to soar into the lead.
"Well, I started with a birdie on 10, which calmed me down a little bit. It's always nice to start with a birdie. I feel like I was really focused out there, very concentrated and hit a lot of good shots," Masson stated. "Just missed one green and made a pretty good putt there for par. So yeah, it was just a really solid round today."
Ciganda, who started the season with a share of sixth in Australia, also played the back nine first on Thursday and birdied two of her first four holes. She later birdied the 18th to make the turn at 3-under.
The Spaniard traded a birdie for a bogey from the first. After three pars in a row, Ciganda caught fire.
Ciganda poured in three consecutive birdie chances from the fifth to jump within one of the lead at 6-under. However, she tripped to a bogey at the eighth to dip two behind.
"I played really good (on the par-3s) and I think the difference was that I made a lot of putts today. I was playing very good the last week, so I was feeling comfortable with my game," Ciganda admitted. "I was patient out there and just to enjoy the beautiful golf course. I'm very happy with my round."
NOTES: Masson's best previous score was a 65 in the second round of the 2011 Women's British Open ... Stacy Lewis struggled to a 1-over 72 ... Ciganda was the Ladies European Tour Order of Merit winner and the tour's Rookie of the Year as well ... Coleman, 17, qualified by shooting 68 on Monday via the High School Shootout ... Suzann Pettersen, last week's winner in Hawaii, carded a 70 in round one.