Thompson, of Coral Springs, Fla., shot a 68 to open a three-stroke lead over Jaye Marie Green of Boca Raton, Fla. The 14-year-old Thompson won the championship in 2007.
My ball striking has gotten a lot better in the last four days, and I am making birdies, said Thompson, who finished third in the tournament last year.
Vogel, of Cooper City, Fla., came into the round tied for second. He made seven birdies on a rain-slowed course to pull two strokes ahead of Jordan Spieth of Dallas, who finished second in the tournament last year.
Vogel, the son of PGA player Joe Vogel, will head off to Southern California after the tournament.
This is what we live for and this is one of the best tournaments in the country, Vogel said. Playing well right before you head off to college really lifts you up a lot.