Nate Diaz and Jorge Masvidal are moving their heated rivalry from the Octagon to the ring -- the two MMA superstars just announced they're going to duke it out once again ... this time, in a 10-round professional boxing match.
The light heavyweight fight is being dubbed "Last Man Standing" ... and will settle the score after their first fight -- for the UFC's inaugural BMF belt -- ended in controversy.
Of course, Masvidal won by TKO at UFC 244 back in 2019 .