Cam Long added eight points, 10 rebounds and six assists as the Patriots won their eighth consecutive season opener.
Harvard, which was led by 22 points and 16 rebounds by Keith Wright, struggled in its first game without Jeremy Lin, who is now with the Golden State Warriors. The Crimson shot just 32.7 percent from the field and committed 24 turnovers, leading to 24 points by George Mason.
Hancock had the hot hand in the first half, scoring nine points and spurring an 8-0 run that pushed George Mason to a 21-14 lead with 7:18 remaining in the half.
In the second half, Andre Cornelius had consecutive layups off steals during a 14-0 run that extended the Patriots' lead to 53-33 with just over 9 minutes to play.