What do these fighters have in common?

[RJJ-94-02=GOAT]

A bit of trivia here. Three separate links/questions, all the fighters in each group have one common link.

Group 1.
Oleksandr Usyk
Daniel Jacobs
James DeGale
Demetrius Andrade
Carlos Gongora.

Group 2.
Miguel Cotto
Daniel Ponce De Leon
Brian Viloria
Michael Katsidis
Jeff Lacy.

Group 3.
Erik Morales
Randall Bailey
Hassan N’Dam N’Jikam
Pablo Cesar Cano.