Saint Louis went scoreless for three-plus minutes as George Mason extended its lead to 57-46 after Kameron Murrell's 3-pointer. The Billikens pulled to 68-63 on Aaron Hines' 3-point play with six minutes left.
George Mason's Jaire Grayer answered with a 3-pointer to start a 10-2 run for a 13-point lead with three minutes left and the Patriots made all 12 of their free throws down the stretch.
The Patriots entered the game ranked last in the conference in scoring offense, averaging 63.4 points. They had 64 points with eight minutes remaining.
Mike Crawford led Saint Louis (6-11, 1-4) with 22 points.