Many people might disagree with Javier Mendez ’s pick for UFC lightweight champion Islam Makhachev ’s toughest fight. Makhachev (26-1 MMA, 15-1 UFC) has been dominant for the most part, but a few fighters have given him competitive fights during his career. Outside of his knockout loss to Adriano Martins in 2015, Makhachev has never lost.