The Bears (9-8, 5-2 Atlantic Sun Conference), who had lost in two previous trips to S.C-Upstate, won their fifth game in a row.
Mercer erased a 12-5 S.C.-Upstate lead with a 15-3 run to pull ahead 20-15. The Spartans (1-15, 1-6) held the Bears to only two points in the final 4:35 of the first half and trailed 32-30 at the break.
After tying the score at 32, the Spartans were limited to a Mezie Uzochukwu 3-pointer during a 10-minute stretch as Mercer built a 48-35 lead.
S.C.-Upstate drew within 50-48 with 4:39 left, but could get no closer.
Mercer outshot S.C.-Upstate from the field 43.8 percent (21-for-48) to 30.4 percent (21-for-69).
Nick Schneiders led the Spartans with 21 points.