Fullah scored six points and posted a block during a key 16-3 first-half run that turned a 5-4 deficit into a 21-7 advantage.
Charleston Southern (14-9, 9-3 Big South Conference) took its largest lead of the game, 58-33, on a Cedrick Bowen dunk with 13:20 left to play.
Joshua Clyburn tallied 15 points and eight rebounds, Khalid Mutakabbir added 11 points and Eric Washington chipped in 10 for Presbyterian (7-20, 4-9), which got just seven points off the bench. The Buccaneers' bench contributed 29 points in the win, led by Bowen's nine.
Charleston Southern outshot Presbyterian 45 percent (27 of 60) to 37 percent (20 of 53) and collected a 36-33 rebounding edge. The Buccaneers forced 13 turnovers, on the strength of 10 steals, and scored 14 points off those errors.
NCAA title game hero Kris Jenkins said he will withdraw his name from the NBA draft and return to Villanova for his senior season.
Andy Katz breaks down the likelihood of Villanova, Syracuse, North Carolina or Oklahoma making a run to the Final Four next season.
Florida State has announced that Xavier Rathan-Mayes will return to the court for his junior season. The 6-foot-4 guard declared for the NBA draft last month but did not hire an agent.