Former UFC lightweight champion Sean "The Muscle Shark" Sherk announced his retirement from mixed martial arts on Monday.
Sherk exits the sport holding a career record of 36-4-1, as well as a UFC mark of 8-4.
Sherk began his career in 1999, fighting largely in regional shows throughout the midwestern United States. His big break came four years later, when Sherk, then undefeated with a record of 19-0-1, lost a unanimous decision to UFC welterweight champion Matt Hughes.
Sherk would win 11 more fights before returning to the UFC in 2006. After splitting matches against Georges St-Pierre and Nick Diaz, Sherk dropped to 155 pounds and outpointed Kenny Florian to claim the newly reintroduced UFC lightweight championship. He defended the belt just once, thoroughly outwrestling Hermes Franca, before failing a post-fight drug test and being stripped of the title.
Sherk subsequently lost to B.J. Penn, and never again entered the title picture.
Nonetheless, Sherk retires at the age of 40 having only lost to men who have worn UFC gold around their waists.
He last competed September 2010 at UFC 119, where he won a split decision over Evan Dunham. The performance earned Sherk ‘Fight of the Night' honors for the third time in his career.