Jakob Gollon added 10 points for the Bears (12-7, 4-2 Atlantic Sun Conference), who used a strong run out of halftime to seal the victory.
Tied 31-all at intermission, Cecil dropped in a layup and knocked down a 3-pointer on back-to-back Mercer possessions to fuel a 14-1 run to begin the second half. The Bears led the rest of the way, outscoring the Spartans 42-35 in the second half.
Torrey Craig scored 17 points and Ricardo Glenn had 16 for the Spartans (9-8, 3-2), who have lost three of their last four.
The Bears have won five straight against the Spartans, and hold a 6-2 all-time advantage in the series.