Floyd Mayweather's controversial Muhammad Ali 'GOAT' debate

Floyd Mayweather has ranked his greatest boxers of all-time and he had no hesitation placing himself at No.1 before explaining why legend Muhammad Ali was not close.

Mayweather appeared on ESPN to give his take on the ‘GOAT’ of boxing and had such legends as Ali, Joe Lewis, Rocky Marciano and Sugar Ray Robinson to choose from.

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But without hesitation, the retired undefeated star chose to throw his name at the top of the five-person list.

He also explained why he considered himself the GOAT.

"He's beat more world champions than any other fighter in a shorter time and less fights than any other fighter," he said.

"Landed punches at the highest percentage and took less punishment. He's been world champion 18 years in five different weight divisions."

When he finished the list, Mayweather controversially placed Ali fifth.

The ESPN host questioned how he could place Ali fifth, considering he is widely regarded as the best boxer ever.

While Mayweather praised Ali’s cultural impact for African Americans, he stopped short of claiming he was the best boxer of all-time.

"Ali, only one weight class and really lost to Ken Norton three times," he added.

"What he did is he stood for a cause in an era when African Americans didn't stand up for their people."

Mayweather rounded out his list with Roberto Duran second, Pernell Whitaker third and Julio Cesar Chavez fourth.