American teen Lexi Thompson fired a four-under 68 on Friday to grab a two-shot lead following the first two rounds of the LPGA Tour's Navistar Classic.
Thompson, 16, reached 10-under 134, two strokes in front of fellow American Stacy Lewis and Becky Morgan of Wales.
"I'm playing smart and just making birdies," Thompson said. "I'm just trying to do my best. That's all I can do."
Meena Lee, who came within one shot of tying the course record with an eight-under 64, is third at seven-under 137.
The tournament appears to bring out the best in Thompson. She was a 14-year-old amateur two years ago when she was tied for the Navistar lead after two rounds before finishing 27th. Last year she tied for 16th as a professional.
"I remember teeing off like in the last few groups, but I don't remember really how I played," Thompson said. "I don't know. I just love playing here."
Italy's Giulia Sergas, South Korean Seo Hee-Kyung and first-round leader Jennifer Johnson are all tied at six-under 138.
Johnson fired a one-over 73 on Friday.
"Every day, every tournament is just a learning experience," said Johnson.
"Being at the top of the leaderboard, that's new for me. Hopefully, I can end the year with a couple more on top of the leaderboard."