By Edward Chaykovsky

WBC/WBA welterweight champion Floyd Mayweather Jr. (48-0, 26KOs) caused a stir among some fans and boxing historians, when he presented his selection for the Top Five fighters of all-time.

Appearing on ESPN Deportes, Mayweather ranked himself at number 1, followed by Robert Duran at 2, Pernell Whitaker at 3, Julio Cesar Chavez Sr. at 4 and Muhammad Ali at number 5.

He left out Sugar Ray Robinson, who is regarded by many as the best fighter of all-time. Joe Louis, Sugar Ray Leonard and Rocky Marciano were also left out.

Mayweather explained his ranking of Ali at five when questioned about his decision. Some fans felt the comments were disrespectful considering Ali's very high level of competition.

"Muhammad Ali lost to Leon Spinks and Leon Spinks only had seven fights when he beat him," Mayweather said. "Muhammad Ali was only at one weight class and Ali really lost all three times to Ken Norton. So this is me just being honest. What Ali did was he stood for a cause in an era when African-Americans didn't stand up for their people. He stood up for a strong cause in his era."

And explained the reason for ranking himself at number 1.

"He's beat more world champions than any other fighter right here," Mayweather said of himself. "He's done it in a shorter period of time than any other fighter up here. And he's done it with less fights than any other fighter up here. Record-breaking numbers all around the board -- pay-per-view, live gate, landed punches on the highest percentage and took less punishment."

As far as ranking Chavez and Whitaker ahead of fighters like Louis and Robinson, Mayweather said:

"[Whitaker] didn't lose until the end of his career. He beat Chavez for real, and I'm a Julio Cesar Chavez fan," Mayweather said. "Julio Cesar Chavez was 80-0 before he lost (actually 89-0-1), and he went to different weight classes."