Sean Sherk

Sherk made his UFC debut at UFC 30, where he defeated Tiki Ghosn.[12] After going 5–0–1 outside the UFC, he was brought back to fight Jutaro Nakao at UFC 36, a fight which Sherk won via unanimous decision.[12] On September 27, 2002, at UFC 39, Sherk defeated Benji Radach when the fight was stopped due to a cut Radach had received.[12]

Sherk was then chosen to fight Matt Hughes for the UFC Welterweight Championship on April 25, 2003. Sherk lost the fight via unanimous decision after going five five-minute rounds.[12] In a back and forth battle, Sherk won two of the overall five rounds, becoming the first and only fighter to ever fight a full five round fight with then-champion Matt Hughes.[13]

Following his loss to Hughes, Sherk fought three more times in 2003, winning all three bouts.[12] In 2004, he signed with Pride and made his debut with the Japanese-based organization at Pride Bushido 2. Sherk defeated Ryuki Ueyama via unanimous decision, in what was his only outing in the company.[12]

According to Sherk's website, the Japanese fans are the ones responsible for giving him the nickname "The Muscle Shark." While he was popular in Japan, Sherk found it difficult to travel and support his family and found he could make a better living fighting as a main event on local shows. He also cited his lack of health insurance for making this decision.

Sherk as the UFC Lightweight Champion

Sherk was invited back to the UFC in 2005 for a fight with Georges St. Pierre. Sherk lost by TKO,[14] but was given another fight in the UFC at UFC 59, Sherk demonstrated that he was able to stand and strike with the more documented striker in Nick Diaz as well as mixing his combination very well with his takedowns, he defeated Nick Diaz via unanimous decision.[15] During the post-fight interview, Sherk stated his intention to drop down in weight to the lightweight division.[15]

In October 2006, at UFC 64, Sherk won all five rounds using his superior wrestling and ground and pound and defeated Kenny Florian via unanimous decision to win the UFC Lightweight Championship.[16] With this win, Sherk became the first UFC Lightweight Champion since Jens Pulver vacated the title in 2002.[16] Sherk fought the bout with a torn rotator cuff and was forced to rehabilitate afterwards.[17]

In July 2007, Sherk successfully defended his title against Hermes França at UFC 73.[18] After the fight, the California State Athletic Commission (CSAC) announced that Sherk had tested positive for Nandrolone, a banned steroid, in a urine test the day prior to the fight. After testing positive for 12 ng/ml of Nandrolone, Sherk was fined $2,500 and suspended from competing in California for one year.[19] Sherk's suspension was reduced to six months after appealing his allegations on December 4, 2007, making him eligible to fight in early January 2008.[20] Sherk argued that errors were made in lab testing procedures. He asserted that the lab had failed to properly test the vials used in earlier, positive tests for any remaining steroid content, which may have resulted in his sample becoming contaminated.[21] Quest Diagnostics and the CSAC denied any errors were made.[21] Following the CSAC's decision to uphold the results of the positive steroid test, the UFC officially stripped Sherk of his UFC Lightweight Championship.[22] At UFC 80, B.J. Penn defeated Joe Stevenson to win the vacant title.[23] After the fight, UFC president Dana White announced that Penn's first title defense would be against Sherk, who was reinstated by UFC in April 2008, and has tested clean ever since.[24] Sherk and Penn fought at UFC 84 on May 24, 2008. Sherk lost by TKO in the third round after failing to answer the fourth round bell.

Sherk fought Tyson Griffin at UFC 90: Silva vs Cote, in a fight with title contention implications. In a three-round war, Sherk won by unanimous decision, earning him Fight of the Night. In the first round Sherk was putting the pressure on Griffin from the very beginning scoring take-downs and taking Griffins back. Throughout the second and third rounds Sherk took Griffin down once more and the rest remained an exciting striking battle between the two. Sherk demonstrated very crisp and technical striking that night.

Sherk next fought Frankie Edgar at UFC 98 losing via unanimous decision. Sherk again found himself in trouble with an athletic commission post fight, after he ran from the arena while still in his fight shorts and no shirt before supplying a post fight urinalysis. He was contacted by commission officer Keith Kizer and told to return to the arena immediately or face his license being revoked. Sherk returned within the hour and provided a urinalysis and tested clean, but was still suspended 45 days for the actions.[25]

Sherk was scheduled to face Gleison Tibau at UFC 104, but was forced off the card with an injury. He was replaced by Josh Neer.[26]

Sherk was scheduled to face Rafaello Oliveira on January 2, 2010 at UFC 108.[27] However, due to an injury to Tyson Griffin, Sherk was promoted to the main card to fight Jim Miller.[28] Sherk did not compete at UFC 108, pulling out due to injury. Sherk suffered a cut above his right eye requiring several stitches.

Sherk was expected to face Clay Guida on March 21, 2010 at UFC on Versus: Vera vs. Jones,[29] but Sherk was forced off the card with yet another injury.[30]

After a 16-month hiatus, Sherk returned on September 25, 2010 at UFC 119 and defeated Evan Dunham via split decision in a bout that earned Fight of the Night honors.[31]

Sherk was planning a fall 2011 return after rehabbing past injuries, but no fights for him came to fruition.

After rehabbing a litany of injuries over the past few years, Sherk indicated in October 2012 that he was still planning a return to the UFC and hoped to return sometime in early 2013.[32]

On September 2, 2013, Sherk formally announced his retirement from MMA fighting.[33]

On February 20, 2016, Sherk verbally expressed that he would end his retirement to fight Royce Gracie in Bellator. He declined any indication of a UFC return.[34]

• Ultimate Fighting Championship
  • UFC Lightweight Championship (One time)
  • One successful title defense
  • Fight of the Night (Three times) vs. Kenny Florian, Tyson Griffin, Evan Dunham
• PRIDE Fighting Championship
  • One of only two UFC Lightweight Champions to compete in PRIDE FC