The top-seeded Retrievers used a 25-2 run in the game's first 10 minutes to build a 41-23 at the half.
The Hawks closed to 61-51 with just under nine minutes left in regulation, but ran out of gas.
Ray Barbosa scored 14 and Jay Greene added 12 points by making four of six three-pointers for the Retrievers (24-8), who won a tournament title for the first time in school history.
Maryland-Baltimore County will enter the NCAA Tournament next week with 12 wins in its last 13 games overall.
Joe Zeglinski led Hartford with 17 points and three rebounds.
Michael Turner scored 16 points and Jaret Von Rosenberg added 15 for the second-seeded Hawks, who finished the season with an 18-16 record.