Ceola Clark added 18 points and Obi Emegano and Terell Parks 15 apiece for the Leathernecks (9-5, 4-2 Summit), who have won three in a row.
Frank Gaines scored 30 points, including four 3-pointers, to pace the Mastodons (9-7, 3-4). But Mario Hines was next in line with just nine points for IPFW, whose two-game winning streak ended.
Houpt went 7 of 9 from 3-point range to pace Western Illinois’ 9-for-12 onslaught from long distance. The Leathernecks shot 51 percent overall.
IPFW led early, but Houpt’s 3-pointer with 11:01 to go in the first half put the Leathernecks ahead for good at 21-19. The lead peaked at 14 in the second half.
Western Illinois’ Tommie Tyler was ejected with 38 seconds left.