Brock Lesnar

History: Brock Lesnar defeated Randy Couture for the UFC Heavyweight Championship at UFC 91 on November 28, 2008. Frank Mir then defeated Antonio Noguira at UFC 92 for the interim title. This match set up Lesnar vs. Mir at UFC 100 for the undisputed Heavyweight Champion. Lesnar won at UFC 100 in the 2nd-round knockout to become the undisputed heavyweight champion.

Lyoto Machida

History: Lyoto Machida became the Light Heavyweight Champion at UFC 98 on May 23, 2009, by defeating Rashad Evans. This fight was the first fight ever in UFC history to have an undefeated champion face an undefeated challenger. Machida was dominant throughout the fight and won with a 2nd-round knockout.

Anderson Silva

History: Silva is without a doubt the best pound-for-pound fighter in the UFC right now. Silva won the middleweight championship at UFC 64 on October 14, 2006, and hasn’t lost since. Silva defeated Rich Franklin with a 1st-round TKO.

Georges St. Pierre

History: GSP first won the welterweight championship at UFC 65 on November 18, 2006, by defeating Matt Hughes. He lost the title shortly thereafter at UFC 69 to Matt Sera. GSP regained the interim title on December 29, 2007, at UFC 79 by defeating Matt Hughes once again. This match set up a bout for the undisputed welterweight championship against Matt Sera at UFC 83. GSP defeat Sera at UFC 83 on April 18, 2008 to become the undisputed champion.

BJ Penn

History: BJ Penn won the lightweight title on December 19, 2008 by defeating Joe Stevenson at UFC 80 in England. Sean Sherk was the previous champion, but was stripped of the title after testing positive for steroids. Penn defeated Sherk at UFC 84 to solidify his status as Lightweight Champion.