The Patriots (5-2) led by as many as 16 and 35-22 at halftime.
The Rams (1-6) pulled ahead 38-37 with 12:44 remaining, with Xavier Munford scoring eight points in the 16-2 run, but their lead lasted just 21 seconds.
The game was tied three more times before George Mason built a five-point lead, capped by a Wright layup with 3:09 left.
Rhode Island got within two, at 54-52 with 2:10 left, but missed its final three field goal attempts, including Nikola Malesevic's 3-point try with 3 seconds remaining.
George Mason had a 50-31 rebounding advantage, and its 19 offensive boards resulted in 22 second-chance points.
Munford's 24 points led the Rams, who made only 13 of 26 free throw attempts.
Wisconsin forward Nigel Hayes has withdrawn from the NBA draft and will return to the Badgers for his senior season.
Recruiting reporter Jeff Borzello has gotten grilled for his selections of underachieving and overachieving college basketball programs. He joins Phil Murphy to explain his rankings.
UConn center Amida Brimah and guard Rodney Purvis have withdrawn from the NBA draft and will return to school for their senior season.