Lexi Thompson back on top in Alabama

Last year, Thompson became the youngest champion in LPGA Tour history at age 16, winning by five strokes. Fifteen-year-old amateur Lydia Ko broke the record last month in the Canadian Women's Open.

Thompson had nine birdies in her bogey-free round on the links-style Senator course at the Robert Trent Jones Golf Trail's Capitol Hill complex. She missed only one green in regulation and had 26 putts.

"It feels really good getting a first round of 63 under my belt, but you just have to take it one shot at a time," Thompson said. "Can't get ahead of yourself in this game, so just going to hope to play like I did today for the next three rounds."

Mika Miyazato and Lindsey Wright shot 63 in the 2010 event. Thompson's previous best score on the LPGA Tour was a 65 in the final round of the Mobile Bay LPGA Classic.

She missed a birdie putt on the 18th hole by about 6 inches.

"I wasn't thinking about the course record, I was just trying to put a good stroke on it like every other putt," she said.

Following the pattern she set last year en route to her lone tour victory, Thompson had breakfast at the Waffle House down the street from the course. The plate of egg whites, wheat toast, hash browns and bacon was prepared specially by Thompson's favorite cook, Valerie Perry.