Dieudonne became the 17th player in Terriers' program history to reach 800 career points and 600 rebounds.
BU (11-11, 4-5 Patriot League) outrebounded Army 45-33.
The Black Knights' Kyle Wilson made three free throws at the end of the first half to knot the score at 33. His jumper to start the second gave Army its last lead of the game.
After Wilson tied it at 46, Mosely hit a 3 with 13:01 to play, which triggered a 14-5 run by the Terriers over the next four-and-a-half minutes. Mosely hit another 3 with 3:46 to play to push the lead to 65-56.
Wilson finished with 25 points and John Emezie added 11 for Army (12-8, 3-5). Wilson ranks fifth in Army history with 1,827 points.