Gracie Jiu-Jitsu Student PUMMELS Alleged Robber (BLOODY MUG SHOT)

An alleged home invader learned the hard way ... you mess with a Gracie Jiu-Jitsu student, you leave with a BROKEN FACE!!

The dude with the busted grill is Josue Ortiz -- who allegedly tried to steal tools from an open garage in Fort Myers, FL ... when he was confronted by the homeowener.

Unfortunately for Ortiz, the guy defending the casa was Brian Burch -- who's not only physically imposing, but also has wrestling experience and trains at the local GJJ gym.

Burch says Ortiz got violent with him ... so he proceeded to beat his ass.

After smashing his nose, cops arrived and arrested Ortiz ... who left a big, bloody stain on the driveway.

Burch is being hailed as a hero ... especially by his neighbors who say the beating will serve as a crime deterrent.