Malcolm Lemmons, who made all three of his 3-point attempts, chipped in 11 points for Niagara.
Niagara took its first lead, 12-11, at the 9:23 mark of the first half but Mark Nwakamma hit a layup to put Hartford (5-5) back up by one. The Purple Eagles, however, outscored the Hawks 25-7 over the final 9 minutes of the half to take a 37-20 advantage into the break.
Niagara (4-6) extended its lead to 21, 51-30, behind a 3-pointer from Lemmons. Lemmons' third trey of the night gave the Purple Eagles a 59-36 lead with 11:26 left to play.
The Purple Eagles shot 50 percent (27 of 54) from the field -- including 7 of 14 from deep.
Nwakamma was Hartford's lone player in double-figures with 14 points.