Devon Beitzel scored 13 of his 19 points in the second half as Northern Colorado ended Montana's five-game winning streak with a 63-45 victory on Thursday night.
Beitzel made only 2 of 4 shots in the first half, but the Big Sky's leading scorer closed the game with the last six points for Northern Colorado (7-7, 3-0).
Elliott Lloyd added 12 for the Bears, who are off to their first 3-0 start in their five years in the conference.
Will Cherry had 11 points for Montana (10-5, 2-1). No other Grizzly player had more than eight as the team shot only 33 percent from the field.