The Highlanders (7-9) were up 26-24 at the half, but rattled off a quick eight points when play resumed, pumping the lead to 34-24 and never letting UMBC back into it.
Lynn, a sophomore, scored 20 and has scored 20 or more in eight games this season. Coleman and Willis each scored 12 and Howard 10 for NJIT.
The Retrievers (2-11) were forced into 21 turnovers on 13 NJIT steals (four each by Lynn and Willis). Cody Joyce led UMBC with 16 points, his seventh game in double figures.