Bellew got the chance to fight for the title after reigning champion Grigory Drozd vacated it due to injury, but it looked like Makabu might win after sending the home favourite to the canvas in the third round.
But Bellew recovered and delivered a barrage of left hooks in the third round that floored Makabu, with the referee intervening.
It was a glorious moment for Bellew, who won a world title at the third attempt after previous bouts against Nathan Cleverly and Adonis Stevenson had ended in defeat.
After a routine defence against BJ Flores, Bellew stepped up to heavyweight to settle his rivalry with David Haye, with two successful – and lucrative – fights.
He returned to cruiserweight to take on undisputed champion Oleksandr Usyk, but lost and subsequently retired.