The undefeated American boxer, Floyd Mayweather, will attempt to match Rocky Marciano’s record of 49 unbeaten run when he squares up against Andre Berto on September 12.

The former Welterweight champion, Berto, has 30 wins and three losses before the bout with his fellow American.

Britain’s Amir Khan had hoped for a September fight with Mayweather, after beating Chris Algieri in June.

However, Mayweather has instead opted for an opponent who has lost three of his last six fights, with Berto suffering reverses to Victor Ortiz and Robert Guerro, both of whom have also been beaten by Mayweather.

If he wins, Mayweather’s record will equal that of legendary 1950s American Heavyweight Marciano, who retired from the sport without suffering a professional defeat.