The sixth-seeded Colonials (21-11) advanced to the quarterfinals to face No. 3 Rhode Island on Friday at Barclays Center.
George Washington shot 55 percent in the first half and jumped out to a 13-point lead. Kevin Larsen had 10 points and 15 rebounds.
George Washington responded with an 11-0 run. Kethan Savage capped the surge with a scoop shot while getting fouled. He hit a free throw to complete the three-point play and make it 61-46 with 7:21 remaining.
The Colonials, who lost five of seven in February, have won three straight in March.