(Taken From Wikipedia)
At the age of 19, Belfort came to the United States to compete. In his first sanctioned mixed martial arts match, an event called Superbrawl in Hawaii, his opponent was Jon Hess, whom the young Brazilian defeated in 12 seconds by knockout, despite Hess having a seven-inch height advantage and an over 100-pound weight advantage over Belfort.
Ultimate Fighting Championship:
Soon after, he moved on to compete in the UFC, where he was given the nickname The Phenom. He beat two fighters in his debut event in the UFC, winning the UFC 12 Heavyweight Tournament. At age 19, Belfort became the youngest fighter to ever score a victory inside the octagon. Belfort’s next match saw him score a technical knockout (TKO) against the UFC 6 runner-up Tank Abbott in a non-tournament fight, knocking Abbott down and finishing him with a ground and pound attack.