Monmouth (11-19, 5-14 Metro Atlantic Athletic Conference) used a 21-8 spurt early in the game to open a 25-13 lead midway through the first half. The Hawks later went on a 10-2 run, pushing their lead to 15 with 6:25 left before intermission.
Monmouth led 41-25 at halftime and scored 13 of the first 15 points in the second half to make it 54-27 with 15 minutes to go and led by as many as 32.
Deon Jones added 16 points for the Hawks, who made 26 of 51 field goals and 6 of 10 from 3-point range.
Antoine Mason led Niagara (6-24, 3-16) with 15 points.
The Purple Eagles shot 31 percent from the field and made just 1 of 13 3-pointers. They committed 24 turnovers.