Floyd Mayweather Jr and Manny Pacquiao 's fight will be the richest ever . Sportsmail 's Jeff Powell is counting down the ring 's most significant fights . Joe Frazier v Muhammad Ali in New York in 1971 is the eighth in the series . Smokin ' Joe was two-belt champion bizarrely backed by conservatives . Ali was darling of young blacks after refusal to fight in Vietnam .
Floyd Mayweather Jr and Manny Pacquiao 's fight will be the richest ever . Sportsmail 's Jeff Powell is counting down the ring 's most significant fights . Joe Frazier v Muhammad Ali in New York in 1971 is the third in the series . Smokin ' Joe was two-belt champion bizarrely backed by conservatives . Ali was darling of young blacks after refusal to fight in Vietnam .