Jon Jones and Daniel Cormier couldn't wait until September 27 to fight ... so they brawled Monday in the middle of the MGM in Las Vegas ... and this one didn't look fake at all.
Jones and Cormier got nose-to-nose, which Cormier was not into ... so he shoved Jones away. Clearly Jones was not pleased, so he went after Cormier and the two knocked the backdrop over before tumbling off the stage.
For his part, Jones wrote, "yo, DC you suck. you suck. you gonna chop me over the neck and get beat up - And I had you on your back - what - in 6 seconds - you suck. you felt so weak."
UFC 178 is gonna be awesome!