What does the saying "you have to really beat the champ to take his title" mean?

[Bill Paxtom]

The 1st time the phrase was 'coined'.

Joe Louis vs. Jersey Joe Walcott 'I'

Boxing Pundits,

How can you give the Decision to Jersey Joe, when he fought going backwards for most of
the bout. You have to really beat the Champion to take his title.

There is no way a Challenger can win a 'close' Decision over the Champion. The Champion gets
the benefit of the doubt in close Rounds.