The UFC star was involved in a insane altercation in the cage with referee Marc Goddard at the event in the 3Arena.
After Ward got the win over John Redmond, McGregor climbed up and over the Bellator cage and rushed across to celebrate with his teammate.
Bellator 187 took place on Friday at 3Arena in Dublin.
McGregor was grappled by security but ultimately left the cage on his own, returning once more to yell "that was a f-king stoppage" before being ejected from the match by Goddard.
McGregor, who didn't have a corner's license for the fight, jumped on Ward.
McGregor (21-3) hasn't fought in mixed martial arts in 2017.
One can expect McGregor (21-3) to face serious discipline for putting his hands on an official, which could jeopardize his return date, which UFC had hoped would be December 30 for the promotion's New Year's Eve weekend card in Las Vegas.
Unless you've been living under a rock, you're well aware that McGregor mad his much anticipated professional boxing debut against Floyd Mayweather back in August.
After being escorted out of the cage, McGregor promptly returned to the vicinity of the area as he acknowledge the crowd.