The referees and judges for the UFC’s first pay-per-view event of the year have been revealed. California State Athletic Commission’s executive officer Andy Foster provided MMA Junkie with the full list of judges and referees for UFC 311 , which takes place Jan. 18 at Intuit Dome in Inglewood, Calif. In the main event, Islam Makhachev puts his lightweight title on the line against Arman Tsarukyan in a second meeting against Arman Tsarukyan . In the co-feature, Merab Dvalishvili will look to defend his bantamweight title against Umar Nurmagomedov . Working the co-main event will be UFC veteran Chris Leben , who will judge his first UFC title fight.