There was action both inside the ring and outside of it at Sunday night’s AEW event in Chicago … as a fan and a security guard got into a wild fistfight in the stands.

The scene went down at some point during the AEW X NJPW Forbidden Door Pay-per-view at the United Center, when multiple guards tried to pull a fan from his seat.

It’s unclear exactly what the man allegedly did to get the boot from arena staffers … but you can see in video, he was not willing to go quietly.

It took multiple security guards to rip him from his chair … but even as they got him up the stairs — he pulled away from the guards’ grasp, and started throwing punches!

The stadium official on the receiving end of the blows didn’t take the haymakers kindly — and returned fire with several fists of his own.

Eventually, staffers appeared to corral the man and take him from the scene.