A 3-pointer by Garino gave the Colonials an 18-2 lead with 14:38 left in the first half as Fordham made just one of its first nine field goal attempts.
George Washington made 17 of 24 (70.8 percent) field goals in the first half and scored the first 10 points of the second to push its lead to 51-27 with 16:37 to play.
Six-straight points by Eric Paschall pulled Fordham (5-10, 0-6), which has lost six in a row, within 10 with four minutes left.
Paschall led the Rams with 17 points. Mandell Thomas added 15 points, eight rebounds, five assists and three steals.