Desmond Louis' 3-pointer from the corner got Voorhees within 86-80 with 1:50 left and James Williams' 3 less than a minute later made it 88-83. Williams had a steal on The Citadel's next trip and Denzel Bolden made a fast-break layup for a three-point game with 31 seconds left.
Warren Sledge hit 1 of 2 free throws for a two-possession game and Jeffery Mack missed a 3-pointer on Voorhees' final shot.
Quinton Marshall added 18 points for The Citadel (6-4).
The Citadel took a 59-58 lead for its first advantage since it was 17-15. Quayson Williams' go-ahead basket came during an 18-0 run for a 67-58 lead as Voorhees went scoreless for five-plus minutes.
Voorhees was led by Louis' 22 points.