Thrilla in Maputo

The director yelled "cut," the cameras stopped and the crew was packing up for the day. But the action continued in the shantytown close to the airport in Maputo, Mozambique, where Ali's 1974 Rumble in the Jungle was being filmed last year. Despite the lull, Will Smith kept on playing Muhammad Ali, shadowboxing, grooving along the dusty road surrounded by hundreds of adoring kid extras. Suddenly, Smith's feet left the ground and he was floating on a sea of hands. "Everyone starts shouting 'Ali, Ali, Ali,'" recalls director Michael Mann. "So, of course, I unwrapped. We started shooting like crazy. Will...