The teenagers are in command at the first stage of LPGA Q-School.
Lexi Thompson shot a third consecutive 6-under-par 66 Thursday to move to 18 under overall at LPGA International in Daytona Beach, Fla. The 16-year-old pro from Coral Springs, Fla., has built a seven-shot lead on 17-year-old pro Ginger Howard (68) of Bradenton, Fla.
The top 50 and ties in the field of 150 move onto Q-School's second stage after Friday's final round. Thompson and Howard are playing Q-School on special permission from the LPGA commissioner. The LPGA requires members be at least 18.