Gaby Lopez, who took some time off after missing back-to-back cuts, fired an eight-under 63 to grab the first-round lead at the LPGA Tour's NW Arkansas Championship on Friday.
The 24-year-old did not play in the Meijer Classic last week, deciding instead to go home to Mexico and regroup.
The move paid dividends on Friday as she equalled her lowest round in relation to par for her career.
"The golf course is in great shape, the whole environment plays with me instead of against me," said Lopez, who also had an eight under at the Cambia Portland Classic last year.
"I've been working on basic stuff with my coach, Horacio Morales. That makes a big difference."
Seven players are one shot off the lead at seven-under 64: Lee Min-jee, Catriona Matthew, Nasa Hataoka, Moriya Jutanugarn, Lizette Salas, Lee Mi-rim and Aditi Ashok.
A half dozen players finished two back of Lopez at six-under.
Lopez started with three birdies over her first four holes and carried that momentum the rest of the way.
She made six birdies on the front nine to make the turn in 30 and rolled in two more birdies on the back.
Lopez was also brilliant with the putter, needing just 25 putts in her round.
This is the first time that Lopez will take a lead into the second round on the US LPGA Tour. She has three career top 10s, but no titles.
Of the 144 players in the field, 104 finished under par.