The decisive play capped a sequence that saw Louisville miss two of six free throws in the final minute while squandering a 66-62 lead in the final second.
Louisville's Darius Perry fouled Ty Jerome on a 3-point attempt with 0.9 seconds left and Jerome made his first two free throws, before the Cavaliers were called for a lane violation on the third shot, which was a miss.
That gave Louisville the ball out of bounds, with Deng Adel looking to inbound it on the baseline. Adel stepped to his left and was called for traveling.
"I kind of forgot I couldn't move," said Adel, who was consoled by Cardinals teammates after the buzzer. "Usually they allow me to run the baseline [and] will allow running the baseline after a score. I just forgot I couldn't take an extra step, and I was just trying to get it to Darius."
Instead, the ball ended up in Hunter's hands, and, moments later, Padgett was enduring a loss he'll long remember.
Information from the Louisville Courier Journal and The Associated Press was used in this report.