Boxing marks a pair of memorable milestones this weekend, even as the sweet science struggles to retain relevance on the international sports landscape.

On Saturday night in Las Vegas, mercurial Floyd Mayweather is guaranteed the richest purse in ring history - a staggering $41.5 million - when he puts his 44-0 record on the line against Mexico's Saul 'Canelo' Alvarez (42-0) in a clash for the WBC junior middleweight crown.

On Sunday, boxing aficionados around the globe will celebrate the 35th anniversary of Muhammad Ali becoming the first three-time world heavyweight champion in what also turned out to be the last win of his legendary career, a 15-round decision over Leon Spinks at the Superdome in New Orleans.