Mixed martial arts referee Herb Dean will step into the cage tonight for the final time ... as a fighter.

He will "voluntarily" retire from competition after his heavyweight bout with Dave Legeno tonight at Cage Rage Championships 22: "Hard as Hell" at the Wembley Arena in London, England.

Dean -- who relies on kickboxing skills -- will attempt to go out on winning note and improve his average record (2-2) against the man who "submitted Kimo and beat Dan Severn."

Let's hope for his sake the bout isn't stopped prematurely.

Update: For those who missed it, Dean turned in a solid performance before being unable answer the bell to start the second round because of an eye injury.

Here's the video: