Sampson Carter scored 20 points as Massachusetts defeated George Washington 67-61 on Saturday.
The Minutemen (20-5, 7-4 Atlantic 10) handed the Colonials (19-6, 7-4) their first home loss of the season.
UMass shot 49 percent from the floor, including 5 of 15 from beyond the arc. Derrick Gordon added 11 points, while Raphiael Putney put up eight points and nine boards.
Patricio Garino had a big outing for GW, with 20 points and three steals. Isaiah Armwood had 16 points and 8 boards, while Maurice Creek added 11 points.
The game was always going to have hints of a grudge match - it was the first time the Colonials and the Minutemen faced each other since Massachusetts knocked George Washington out of the A-10 tournament last season.