Colgate (1-0) led for much of the first half and by as many as 11 points at 31-20. Monmouth (0-1) rallied back with a 10-0 run in the final three minutes of the first half trailing by one point, 31-30.
The Hawks jumped ahead by seven points in the first five minutes of the second half. Monmouth built its lead to 48-40 before Colgate went on a 14-3 run to go in front 54-51 with 6:20 left in the second frame.
Monmouth cut the lead to one but couldn't get any closer as it struggled from the free throw line in the second frame.
The Hawks shot just 42.9 percent from the charity stripe in the second half. Colgate hit five of its six free throws in the final two minutes to seal the win.