Miller, who led Missouri State (6-10, 2-2 Missouri Valley) with 16 points, scored the final four in the last 1:19 to foil a late comeback by the Ramblers (7-9, 0-4).
Loyola closed the first half on a 10-5 run to grab a 29-23 lead, hitting five shots without a miss. They extended the lead to 33-23 before Missouri State came to life.
Obediah Church slammed two dunks as the Bears went on a 19-8 run to lead 42-41. Loyola climbed back as the Bears went through an extended dry spell. Milton Doyle stole an inbounds pass and drove for a 54-54 tie with seven seconds left, but Loyola was unable to get a final shot off in time.
Eric Peterson led the Ramblers with 18 points, Doyle 13.