George Tillman Jr. "didn't get a lot of sleep," as he tells EW, trying to get one specific scene right in his latest movie, Big George Foreman: The Miraculous Story of the Once and Future Heavyweight Champion of the World.

"What I labored over the most is definitely the George Foreman-Muhamman Ali fight in Zaire," the director recalls of the match dubbed the Rumble in the Jungle. "We shot and did everything specifically to match the fight. And then from a philosophical standpoint, we wanted to really make sure we got that eight-round fight, the three-punch combination. So we did that 45 times; Khris got hit 45 times — the three-punch combination, George's turn to hit the canvas, and Ali turning around. Forty-five times. We knew we were going to fight and hit real boxers. We knew we were doing real punches in the film, but that was just the most famous punch of all time."