THIS IS CRAZY VIDEO!!!
The fighting spilled into the stands at an MMA event in Florida over the weekend -- with punches and chairs thrown everywhere -- and culminated with someone firing a GUN twice!!!
... and TMZ Sports has the unbelievable footage.
Here's the deal ... the Palm Beach County Sheriff's Office is investigating the incident at the RIZE Fighting Championship event which went down on March 20 at the Bamboo Room in Lake Worth Beach.
The event was promoted as a bantamweight championship match between Alexis Fernandez and Filipe Valentim -- but there was more action in the stands than inside the cage .