Brock Lesnar was a champion.
Brock Lesnar . Lesnar won the then WWE Undisputed Championship five months after his main roster debut at the age of 25 , becoming the youngest champion in the title 's history . Lesnar is a five-time world champion in WWE , a one-time heavyweight champion in the UFC , a one-time heavyweight champion in NJPW , and a one-time heavyweight wrestling champion in the NCAA , the only person in history to win a championship in each of those organizations .