The Kangaroos (11-18, 6-7 Mid-Continent) stayed ahead the entire game, leading 45-26 at the half and keeping Western Illinois scoreless for most of the final 4:00.
Jerryck Owens-Murrey was the only player in double digits for the Leathernecks (6-22, 2-11) with 16 points on 6-of-7 shooting. Sammy Hunter added nine points and Troy Okeson had six. David Jackson scored his 1,000th career point in the second half, finishing with five points for the game.
Ayuba shot 7-of-9 from the field and made both of his free throws. Dane Brumagin had a game-high seven rebounds and chipped in eight points.
The teams were even on the boards, at 33 rebounds apiece, but UMKC managed 20 points off turnovers, compared with six for Western Illinois.