Yujeong Son matched the women's course record with a 7-under 64 on Monday to take the first-round lead in the Junior PGA Championship, and U.S. Junior Amateur champion Philip Barbaree topped the boys' leaderboard at 66.
The 14-year-old Son, from Norman, Oklahoma, had eight birdies and a bogey to tie the Miramont Country Club women's record set in the event last year by Ellen Takada.
"It was a good round overall and my putting was great," Son said. "I was hitting my iron shots really close and I had chances for birdie that I eventually made."
Fai Khamborn of Cincinnati was second after a 67.
The 17-year-old Barbaree, from Shreveport, Louisiana, rebounded from bogeys on Nos. 9 and 10 with birdies on Nos. 12-14.
"I told myself just to learn from it and to remind myself not to do that again," Barbaree said. "Today, I learned."
Austin Eckroat of Edmond, Oklahoma, and Jack Snyder of Phoenix were a stroke back.