Leon Spinks defended his WBA world heavyweight title against Muhammad Alibr br Date: September 15, 1978br br Venue: Superdome, New Orleansbr br Ali stance: orthodoxbr br Spinks stance: orthodoxbr br Muhammad Ali lost his undisputed world title in his 11th defence, fighting a seven bout novice. This was one of the biggest upsets in boxing history. It was clear Ali had slowed down and was out of shape when he lost his belts. Seven months later, Ali was attempting to become the first man to be world heavyweight champion for a third time.br br While no one doubted Leon Spinks' amateur pedigree, most observers felt he was rushed into his fight with Ali after just a year and seven bouts in the pro ranks. Spinks proved the dpoubters wrong by pulling off a shock win against Ali. After that fight, Spinks was stripped of his WBC belt for refusing to face Ken Norton and choosing to give a rematch to Ali.