The baddest man on the planet, UFC heavyweight champion Brock Lesnar, is back in the main event for UFC 121, and unbeaten Cain Velasquez is looking to take his belt and become the first man to knock him out. Lesnar proved he had beaten the severe illness that kept him sidelined for a year by withstanding the onslaught by Shane Carwin at UFC 116 and defending his heavyweight title with a slick submission in the second round. His opponent at the Honda Center in Anaheim, California, on October 23, 2010, Cain Velasquez, has already made short work out of the heavyweight division and he promises to make the most of his first shot at the title.

Also on this star-studded UFC 121 card, which is presented by Boost mobile, welterweight star Jake Shields makes his long-awaited UFC debut against perennial contender Martin “The Hitman” Kampmann. Also featured is an exciting welterweight matchup as Diego Sanchez battles Paulo Thiago, while it is teacher vs. student as Matt “The Hammer” Hamill takes on his coach from The Ultimate Fighter, former UFC light heavyweight champion Tito Ortiz. Rounding out the main card is a bout pitting rising heavyweight star Brendan Schaub against veteran contender Gabriel Gonzaga.