Jordan Gregory scored 21 points, including 5 of 9 from 3-point range, and Montana scored the final seven points of the second half in overtaking Idaho State and winning 59-54 on Thursday night.
Keron DeShields scored 13, while Kareem Jamar, the Grizzlies leading scorer (19.9 ppg), was held to seven points.
Idaho State led 30-21 at halftime and maintained the lead in the second period until Gregory hit a trey for Montana, tying the score at 46 with 5:49 remaining. Gregory netted two more 3-pointers sandwiched around a Bengal 3 to go ahead 52-49 with 2:03 to play.
The Bengals scored the next five points and led 54-52, but Mario Dunn landed a trey for Montana to lead 55-54.
The Grizzlies (8-8, 3-4 Big Sky) closed on four free throws and a pivotal steal in securing the win.
Idaho State (6-10, 3-4) was led by Tomas Sanchez with 13 points.