UFC 61: Bitter Rivals was a mixed martial arts event held by the Ultimate Fighting Championship on Saturday, July 8, 2006. The main event was a Heavyweight Championship match between champion Tim Sylvia and former champion Andrei Arlovski. The co-main event was the highly anticipated re-match of TUF 3 coaches Tito Ortiz and Ken Shamrock.

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

WEC 13: Heavyweight Explosion was a mixed martial arts event promoted by World Extreme Cagefighting on January 22nd, 2005 at the Tachi Palace Hotel & Casino in Lemoore, California. The card featured a 4 man Heavyweight Tournament featuring Brandon Vera as well as single fights which saw the likes of Jason "The Punisher" Lambert, Brad Imes, and MMA legend "Mr. International" Shonie Carter compete.

UFC Fight Night 4: Bonnar vs Jardine was a mixed martial arts event held by the Ultimate Fighting Championship on April 6, 2006. The event took place at Hard Rock Hotel and Casino, in Las Vegas, Nevada and was broadcast live on Spike TV in the United States and Canada.