Mini Mayweather and Mini McGregor had a pint-sized showdown leading up to their superfight ... and the results were nothing short of amazing!!

The ounce-for-ounce champ Mini Floyd is set to take on Mini Conor Friday ... and although they may be small, their mouths are just as big as their superstar counterparts.

The 3-round fight is set to go down at Larry Flynt's Hustler Club -- just down the road from T-Mobile Arena -- and the expectations are high. Well .. you know what we mean.