Trivia: Flyweight champ "beats" heavyweight champ

[Slugfester]

The shortest known line is:
Fighting Harada > Eder Jofre > Vicente Saldivar > Ismael Laguna > Carlos Ortiz > Duilio Loi > Chris Christensen > Billy Graham > Joey Giardello > Rubin Carter > Jimmy Ellis


... or is it??

That is quite a chain. I would never have found it. I would have more chance of solving the Reimann conjecture!