Sykes gave UCF a 58-57 lead with a layup, but Jerrold Brooks answered with a layup to bring the game to its 10th tie, 58-58. UCF's Keith Clanton missed a layup with 53 seconds left, giving Southern Miss a chance to regain the lead. But Clanton stole the ball from Dwayne Davis, and the Golden Eagles were forced to foul.
Sykes knocked down the ensuing free throws for the win.
UCF (16-6, 6-2) shot 40 percent (18 of 45) and snapped the Golden Eagles' 10-game winning streak.