Saint Mary's was led by Jackie Nared with 21 points and 11 rebounds, while Danielle Mauldin added 16 points and 12 rebounds. Kate Gaze added 14 points and five assists, while Carli Rosenthal and Morgan Hatten scored seven apiece.
George Washington was led by Shi-Heria Shipp and Danni Jackson with 13 points apiece.
In the first half, the Gaels used a 12-2 run to lead by as many as 12 points. Nared drilled a three-pointer with 4:30 left in the half to put SMC up 30-18. GW ended the half with a small run to pull within 34-26 at the break.
In the second half, GW pulled within eight points at 43-35, before the Gaels went on a 20-4 run, capped by a Mia Greco three-pointer to lead 63-39 with 8:36 remaining.
Leading by 19, the Gaels would later go on a 10-0 run to put the game away. The Gaels led by as many as 32 points before taking the game at 79-49.
For the game, the Gaels shot 49.1 percent from the field, while GW shot 31.7 percent. SMC outrebounded the Colonials 45-33 and forced GW into 17 turnovers.
Saint Mary's is back in action on Thursday when it travels to San Francisco for its West Coast Conference opener. Tip is set for 7:00 p.m. in War Memorial Gym.