Mike Weisner added 11 points and Keron DeShields had 10 for the Grizzlies (16-4, 12-0 Big Sky), who also won their 23rd consecutive Big Sky Conference game -- moving them within one win of Weber State's conference record from 1967-70.
Thomas Reuter led the Eagles (6-16, 4-8) with 11 points. Eastern Washington committed 16 turnovers and shot 37.5 percent from the floor.
The Eagles came out hot, opening the game on an 11-2 run. But Montana made quick work of Eastern Washington's lead, ripping off a 26-3 run and cruising from there. The Grizzlies led by as many as 20 after halftime.
Montana was 9 of 11 from the line, improving upon its 76.9 percent free-throw shooting that ranked fifth in Division I entering the game.