Farad Cobb chipped in with 16 points to help the Mocs (6-9, 1-1).
Tied at 51 with 13:29 left to play, the Mocs went on an 18-10 run to take a 69-61 lead with 4:48 remaining.
Samford (3-12, 1-1) responded with a 9-3 run capped by Raijon Kelly's jumper that made it 72-70 with 2:22 to play.
Both teams went cold from the field over the final 2 minutes. Connor Miller, Clide Geffrard Jr. and Kelly all missed potential go-ahead shots for Samford in the final 1:45, and then Ronrico White connected on two free throws to seal the victory for Chattanooga.
The Mocs were efficient, shooting 57.8 percent (26 for 45) for the game.
Kelly led all scorers with 27 points.