Fighting Floyd Mayweather can be an exercise in frustration.
He typically doesn't overwhelm you with his power, but rather surgically picks you apart with supreme technique and superb punching precision.
During a 2006 fight for the IBF Welterweight Championship, Zab Judah let his frustration get the best of him against Mayweather.
Being out-boxed in the tenth round, Judah delivered a clear low blow to Mayweather before following it up with a vicious overhand right.
A near-riot then broke out in the ring, but the fight was eventually able to continue and Mayweather won by unanimous decision.
Judah was later fined $350,000.