Combat sports are incredibly demanding. Physically and mentally, competitors are required to give it their all. In this case, a Muay Thai fighter suffered a brutal injury to his head while putting it all on the line inside the cage. Jo Nattawut recently faced off against George Mann in a Muay Thai match up for ONE Championship. Nattawut pummeled his way to a unanimous decision victory, but not before causing a massive hematoma on Mann's head. Check out the stunning scene within the video provided above and the photos below. For more MMA news click here.