EXCLUSIVE

Former MMA champ Tito Ortiz has been charged with two counts of DUI ... after crashing his Porsche into a concrete median back in January, TMZ Sports has learned.

The 38-year-old fighter was arrested on January 6th ... when cops say he blew a .12 on the breathalyzer, following the 4am crash on an L.A. freeway.

As we previously reported, Ortiz had been partying at the Playboy Mansion in the hours before the incident.