The Patriots (8-2) trailed 21-20 with 10:35 to go until halftime and outscored the Flames 28-5 the rest of the first half.
Andre Cornelius' layup with 30 seconds left put George Mason ahead 48-26 at the break. The Patriots made 20 of 27 field goals in the first half (74.1 percent). It was their best shooting performance in a half this season.
George Mason, which won its sixth straight, shot 60 percent from the field for the game (33 of 55). Pearson was 7 of 8 shooting and Long 7 of 12. Luke Hancock added 12 points for the Patriots.
George Mason scored 40 points in the paint and 29 off of 17 Liberty turnovers.