Brandon Gfeller scored 15, including five 3-pointers, and the Grizzlies (4-7, 1-0) shot 11 of 31 from distance (35.5 percent).
The lead changed hands 10 times and there were four ties before Breunig made a layup to spark a 10-2 run and Montana pulled ahead 26-20. Breunig scored his 12th point of the half on a dunk to cap a 7-0 run and the Grizzlies led 33-21 at halftime. Gregory scored 13 points in the half.
Gfeller hit three straight 3-pointers and Montana used a 13-2 run to pull away 50-34 in the second half. Gregory hit consecutive 3s for a 60-36 lead with 8:16 to play and the Grizzlies stayed ahead.
Cameron Michael led Northern Colorado (5-7, 0-1) with 15 points