It was the first home loss this season for Mason (11-8, 3-3 A-10).
George Washington (9-8, 3-3 A-10) shot 54.8 percent in the second half and turned a five-point halftime lead (30-25) into an advantage as large as 11 (74-63) with 4:32 left.
Mason got back in it with a 12-3 run to move within two (77-75) with 1:11 to go, but the Patriots could not get a bucket on their final possession, and GW hung on for the win.
“This is a disappointing loss,” Mason coach Kim English said. “We have a ton of respect for GW’s team. It was a game we did not want it to be. They’re the best offense in the A-10. If you try to outscore them, they can beat anybody. We didn’t get our process done.”
Ronald Polite III led George Mason with 19 points (6-of-11 FG), seven rebounds and four assists in 34 minutes.
Josh Oduro – who was named the Atlantic 10 Player of the Week earlier in the day – tallied 17 points, nine rebounds and four assists in 37 minutes.