It's a sucker punch of the highest lowest order. A Romanian soccer fan, upset over a call on the field, stormed the pitch during a match between Steaua Bucharest & Petrolul Ploiesti and punched a Bucharest defender from behind.
Not only did he break the cheek of the player, George Galamaz, but he then set his sites on other players.
That didn't work out too well, though. The attacker was eventually tackled and even kicked by other players before being arrested. You can watch it all unfold below: