McLean was 8 of 16 from the floor with four 3-pointers. James Ford Jr. added 14 points for Quinnipiac (4-4).
Justin Graham scored 17 points to lead Hartford (3-7).
The Hawks used a 13-0 run to tie it at 60 with seven minutes remaining. Quinnipiac missed five shots and had two turnovers, and George Blagojevic and Graham made field goals to give Hartford a 65-62 lead with 2:29 left.
McLean made two free throws and a jumper to give Quinnipiac a 67-66 lead with 1:16 to play.