Floyd Mayweather Jr and Manny Pacquiao 's fight will be the richest ever . Sportmail 's Jeff Powell is counting down the ring 's most significant fights . The first was a boxing match between Muhammad Ali and Joe Frazier in Zaire on March 25, 1974. Race - Jack Johnson v James J Jeffries .
Floyd Mayweather Jr and Manny Pacquiao 's fight will be the richest ever . Sportmail 's Jeff Powell is counting down the ring 's most significant fights . First up is 1910 's Fight for Race - Jack Johnson v James J Jeffries .