BERLIN, GERMANY - JUNE 20: The referee calls the fight due to a medical stoppage against Piotr Hallmann of Poland after being cut by Magomed Mustafaev of Russia in their lightweight bout during the UFC Fight Night event at the O2 World on June 20, 2015 in Berlin, Germany. (Photo by Josh Hedges/Zuffa LLC/Zuffa LLC via Getty Images)
