Jiri Prochazka was a football hooligan in his native Czech Republic until martial arts and an ancient Japanese text inspired him to turn from street fighting to cage fighting -- and become a UFC world champion.

Brock Lesnar has tested positive for an unnamed substance in an in-competition sample taken on the night of his UFC 200 heavyweight victory over Mark Hunt on July 9, the Ultimate Fighting Championship (UFC) says.

American professional wrestler and mixed martial artist Brock Lesnar has been flagged by the U.S. Anti-Doping Agency (USADA) for a possible doping violation.