This event has already taken place, read about the results here

http://mmasoldier.com/2010/10/ufc-121-lesnar-had-no-2nd-rnd-comeback-magic-against-velasquez/

UFC has announced the lineup for UFC 121 that will feature the return of Brock Lesnar who will face off against Cain Velasquez.

UFC.com

Las Vegas, NV (USA) – 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 theheavyweight division and he promises to make the most of his first shot at the title.

Brock Lesnar may have overcome one undefeated heavyweight prospect by submitting Shane Carwin at UFC 116, but he’s got another one already locked and loaded for his next title defense as he faces the undefeated Cain Velasquez. Lesnar (5-1) suffered a onesided beatdown in the opening round of his July 3 title bout against Carwin, coming very close to a technical knockout stoppage on several occasions. After barely making it out of the first round, he came out in the second  and fought back to secure an arm-triangle choke and “Submission of the Night” victory over an obviously winded Shane Carwin.

Cain Velasquez has won all six of his Octagon fights, finishing five of them by way of technical knockout (punches). He trains out of the American Kickboxing Academy (AKA), throws heavy hands and should not have the cardio problems that Carwin displayed. His resume has been impressive, but then again, so was Carwin’s.

Matt Hamill, who is on a four-fight win streak in the UFC will face off against his former coach from the third season of The Ultimate Fighter, Tito Ortiz.  “The Huntington Beach Bad Boy” showed a soft spot in his heart for Hamill during the show and took him under his wing during training sessions. This will be Tito’s first time back in the Octagon since suffering a split decision defeat at the hands of Forrest Grifin in November 2009.

Former Strikeforce Middleweight Champion Jake Shields is now a UFC fighter and will face a well rounded fighter with excellent standup, Martin Kampann.   Jake Shields defeated Dan Henderson in his last fight with Strikeforce and is currently considered as a top Welterweight by various MMA websites and magazines. It would be wise for Jake not to underestimate Kampmann who is coming off a decisive decision victory over highly respected Paulo Thiago and will be looking to move into contender status with a win over Sheilds.

The full scheduled fight card is below the Promo Video,

UFC 121 in Anaheim
Date: Oct 23, 2010Location: Anaheim, California
Venue: Honda Center
Broadcast: Pay-per-view

MAIN CARD:
Champ Brock Lesnar vs. Cain Velasquez (for heavyweight title)
Jake Shields vs. Martin Kampmann
Matt Hamill vs. Tito Ortiz
Gabriel Gonzaga vs. Brendan Schaub
Diego Sanchez vs. Paulo Thiago

SPIKE PRELIMS:
Ryan Jensen vs. Court McGee
Patrick Cote vs. Tom Lawlor

UN-AIRED PRELIMS:
Jon Madsen vs. Todd Duffee
Sam Stout vs. Paul Taylor
Chris Camozzi vs. Dongi Yang