Anthrax were Metal Thrashing Mad at L.A.’s Club Nokia Saturday night, and with good reason.

When a fan jumped on stage during the band’s set, singer Joey Belladonna approached to put his arm around the guy – when a dopey security guard bolted on stage and tackled the two of them hard to the floor in mid-song, bringing things to a crashing halt.

Bassist Frank Bello got tangled up in the ensuing melee, as more security pounced and the pushing and shoving between all parties began. Bello ended up in the pile and appeared to go after the security guy responsible, only to be held back by others working the show.

Guitarist Scott Ian stepped to the mic to state the obvious: “It's pretty smart to tackle the singer. F**king geniuses they got working here, huh? I guess they haven't seen him up here on stage for the last 90 minutes. He's in the band!"

With only a couple of songs left in the show, Anthrax picked up the pieces and finished their set.