Pryor had seven rebounds and seven assists for the Mocs (19-9, 12-3), who stayed one game behind Wofford (13-2) in the Southern Conference standings.
Mercer (15-13, 10-5) pushed ahead early in the second half after a 35-all halftime tie. The Bears led by four, but Chattanooga answered with a 15-4 run to take the lead for good at 51-44.
Darious Moten's 3-pointer pulled the Bears back within five with 1:44 left. The Mocs made 9 of 10 free throws from there to seal it.