One of boxing's legends in his own right, Tyson has always adored Ali. A young Tyson appeared with him on the Arsenio Hall Show in 1989, and Hall tried to stir up a debate about who was better.
"I know I'm great, but can I tell you something?" Tyson said. "In this situation, every head must bow, every tongue must confess, [Ali] is the greatest of all time."
Ali tried to play it off with grace and humility, insisting that Tyson was better, but Iron Mike wasn't having that.
"I don't believe that," Tyson said. "The Champ is very modest. I seen him in the ring with killers, guys that hit much harder than I, and he takes these guys' greatest punches and that's what made him such a champion. Watching Ali gave me a great deal of confidence and deep down inner belief that no there's no man, in his mind, that could beat me."
Some 18,000 people packed the KFC Yum! Centre Friday to honour Ali, and more than 100,000 lined the streets of Louisville during a 19-mile procession through Ali's hometown.
Ali was laid to rest in a private service at Louisville's Cave Hill Cemetery before the public celebration of his life.
"Ali" is the single word inscribed on his headstone, in keeping with Islamic tradition, family spokesman Bob Gunnell said. The Greatest's coffin faces the Islamic holy city of Mecca.