Chris Udofia tied it at 78 with 18.8 seconds left in the extra period, making a pair of free throws. But Iona hurried the ball down the court. Scott Machado drove the lane and kicked the ball back out to Dezouvre near the top of the key, where he swished the winning shot.
Chase Hallam’s long jumper at the buzzer hit the rim and bounced out.
Lamont Jones led Iona (7-1) with 21 points. Machado had 19 points and Mike Glover added 13.
Freshman Brett Olson had 20 points to lead Denver (6-2), which lost for the first time in five home games.