The altercation between Conor McGregor and Nate Diaz happened during a press conference ahead of their bout at UFC 202, which is scheduled for Saturday.
While Diaz and his entourage were walking out of the media event, Diaz could be heard shouting at McGregor, who was speaking to journalists from a table on the stage.
"Hey, f--- your whole team, how about that?" Diaz said.
"You'll do nothing. Shut your f---ing mouth," McGregor responded. "You'll do nothing. You'll do f---ing nothing. Not one of you will do nothing. Get the f--- out of here," an incensed McGregor added before throwing several water bottles at his UFC opponent.
McGregor is currently the UFC Featherweight Champion.
UFC President Dana White was visibly disappointed after he tried to stop McGregor from hurling the bottles at Diaz.
"Sorry guys. See you Saturday," White said abruptly ending the press conference after the squabble.
It's not unusual for professional fighters to engage in a bit of showy bravado before a match; it's a tradition that stretches back to the early days of boxing.