George Mason (11-14, 5-7 Atlantic 10 Conference) has won two of its last three games. George Washington (10-15, 3-9) has lost five of its last six, and is now 0-8 on the road.
Livingston was 4 of 7 from the floor and matched a career-high with nine assists. Grayer, who had three straight double-doubles before a foot sprain limited his play in George Mason's last three games, collected his sixth double-double. Justin Kier added 13 points and AJ Wilson had 11 for the Patriots.
The Patriots had a 14-point lead with 3:16 to play. Watanabe scored nine points during a 17-7 surge that pulled the Colonials to 68-64 with 18 seconds remaining. Livingston shot 4 of 4 from the line to seal it.
Bichi Fuertes: 'Vengo a dar una mano'
El nuevo DT de Colón asume en reemplazo de Eduardo Domínguez.
Georgia's plane slides off runway, delaying trip to Philly until Tuesday
The start of Georgia's road trip to Philadelphia to play Temple was delayed until Tuesday morning after the team's plane slid off the runway Monday night.
Huskies' Thybulle drops in a reverse dunk on alley-oop
Washington G Jaylen Nowell lobs a pass up to G Matisse Thybulle, who finishes with a one-handed reverse dunk.