Ky Howard had 17 points with seven assists for NJIT (3-1). Terrence Smith scored 17 points, Winfield Willis had 15 points, and Damon Lynn added 11 points with six assists for the Highlanders, who have won eight straight home games dating to last season.
Matt Klinewski scored 26 points on 9-of-15 shooting to lead Lafayette (1-2).
NJIT led 44-27 at halftime before the Leopards used a 19-6 run to pull to 50-46 with 13 minutes left. Klinewski scored eight points during the span.
Willis made a pair of free throws to spark a 12-7 surge to stretch NJIT's lead to 62-47, and the Highlanders led by double digits the rest of the way.