Clark hit six 3-pointers en route to 26 points, Johnson finished with 23 points and seven assists, J.J. Mann added 13 points and Blake Jenkins 10 points and seven rebounds for the Bruins, who won their fourth straight regular-season conference championship, the previous three coming in the Atlantic Sun Conference.
Belmont (25-6), undefeated at home this season, led 32-29 at intermission and opened the second half on an 11-3 run to pull ahead 43-32. Tennessee State (18-14), which won the previous meeting 80-69, cut it to 66-62 with 5:07 left but was outscored 16-11 from there.
Belmont, which has won its last five games and 16 of 18, made 22 free throws to the Tigers' five.
Kellen Thornton led Tennessee State with 22 points and 12 rebounds.