Scary moment in the WWE on Monday night ... Seth Rollins was attacked by a fan during "RAW" -- and the wrestler needed droves of security to help get the guy off of him.
It all went down just seconds after the superstar had beaten Finn Balor in the ring at Barclays Center in New York ... when a man left his seat, jumped some railing, and speared Rollins while the 35-year-old was on his way back to the locker room.
Video shot by fans standing next to the altercation is WILD -- the man absolutely rocked Rollins .