The Rams (4-10) trailed 33-28 at the break and by seven a minute into the second half. They then went on an 18-5 run, with Gaston scoring eight points, to take the lead for good.
The Hawks (5-8) got within a point on two occasions, the last time at 49-48 with 10:21 to go, but Smith knocked down two straight 3-pointers to spark an 11-2 run and Monmouth never threatened again.
Fordham, coming off a 73-48 loss to Georgia Tech on Saturday, posted its highest point total of the season, as Mandell Thomas added 12 points and leading scorer Branden Frazier (16.8 points per game) chipped in 11. Ryan Canty had 14 rebounds.
Jesse Steele led Monmouth with 13 points.
College basketball fans should be excited about next season's Jimmy V Classic, an event that will feature Duke's heralded freshman class.
Jeff Goodman logs all the coaching changes following the 2015-16 college basketball season.
Can Josh Pastner keep top talent in Georgia? Will Tubby Smith change his recruiting philosophy at Memphis? New coaches face some difficult questions.