Paulie Malignaggi
Malignaggi knew he had physical shortcomings as a boxer but he made up for them with his work rate and skill. This won him IBF and WBA titles as well as a lot of money. Then UFC superstar Conor McGregor hired him as part of his training camp for the Floyd Mayweather fight. But leaked footage of a knockdown infuriated Malignaggi (via TalkSport).

McGregor never offered him an official fight but it wasn’t over. Malignaggi agreed to fight McGregor’s training partner, Artem Lobov, in a bare-knuckle boxing match. These freak show events were above Malignaggi as a former champion but he didn’t care. Unfortunately, he lost to Lobov and his pride suffered.