This one makes the list not because Barboza was an underdog or that he overcame severe adversity during the fight, no. This one gets in not only for its from-out-of-nowhere factor, but also because it's arguably the single greatest one-shot knockout in the history of MMA. Barboza came to the UFC with a particularly famous arsenal of black-belt Taekwondo skills in his locker, but despite winning his first bout in the organisation via leg kicks, the Brazilian failed to finish his next two opponents. So when Terry Etim travelled to Brazil for his tenth UFC fight, he would've certainly expected a slugfest, but what Barboza produced at UFC 142 was nothing short of magic, and it all came together perfectly. Joe Rogan was providing his usual commentary and just as he screamed the words "risk getting knocked out" Barboza uncorked a ferocious spinning wheel-kick which landed flush on Etim. The Englishman's entire body went stiff as he fell hopelessly to the mat, Barboza himself looked to be in disbelief at what he'd done, let alone the entranced fans inside the HSBC Arena.