20. Bobby Portis vs. Nikola Mirotic
The Bulls’ season was terrible in 2017 and tensions were mounting. Portis and Mirotic didn’t get along at all and continuously trash-talked each other in practice. But suddenly things escalated in a stunning outburst of violence. Ironically, Mirotic started it but came off much worse in the end.

The two young forwards got in a scuffle that left Mirotic with a fractured face and a concussion and Portis with an eight-game suspension. Mirotic charged at Portis twice before Portis threw a punch and connected with Mirotic’s face. It’s probably the worst beef in recent NBA history.