Evansville (14-14 Missouri Valley Conference) jumped ahead early and lead 32-29 at the half after shooting 66.7 percent from the field.
Bradley Strickland added 14 points on 6-of-6 shooting to round out the double-digit scoring for the Purple Aces.
Two good free throws by Webster capped a steady comeback effort for Evansville and tied the score at 56 with 4:55 left to play. His jumper seconds later pulled the Aces ahead by two and they never looked back.
Gulina sparked a late Samford rally and the Bulldogs pulled within two, 65-67, on a 3-pointer by Merritt with 13 seconds left on the clock.
But it was the closest the Bulldogs would get after two good free throws by Evansville's Kyle Anslinger sealed the game.