Townes finished with 18 points, five rebounds - all offensive - and five steals, all career-highs for the freshman. Darian Anderson led the Knights (5-6) with 23 points.
Fairleigh Dickinson trailed by as much as 16 in the second half but whittled the deficit to one with 4:16 left after a pair of Townes buckets. Townes made a pair of free throws to give FDU a one-point lead with 13 seconds left, but Towson's Eddie Keith made 1 of 2 from the line with one second left to force overtime.
The Tigers scored the first four points of overtime before Stephan Jiggets and Anderson drilled 3-pointers, then Townes' layup sealed it.
Towson (7-6) led 46-32 at intermission, scoring the last eight points of the half. Four McGlynn led Towson with 27 points.