KOTC 23: Sin City was an event held on May 16, 2003 at the Orleans Hotel Casino in Las Vegas, Nevada, United States.

WEC 6: Return of a Legend was a mixed martial arts event promoted by World Extreme Cagefighting on March 27, 2003 at the Tachi Palace Hotel & Casino in Lemoore, California. The event was centered around the return of MMA superstar Frank Shamrock taking on Bryan Pardoe. Shamrock had been retired and not competed in MMA since December 2000.