The final UFC event of 2011 saw many upsets and the end of a former UFC heavyweight champion's short, but successful career.
Brock Lesnar returned from an extensive break from the sport to take on former Strikeforce heavyweight champion Alistair Overeem.
It took less than three minutes for "The Demolition Man" to tear through the former WWE superstar, and with his second consecutive knockout loss, Lesnar retired from the sport with an overall 5-3 record.
In the co-main event, Nate Diaz upset Donald Cerrone over three rounds to win an exciting and dominant unanimous decision.
Other fighters who came up short include Jon Fitch, Vladimir Matyushenko and Nam Phan. This is what's next for them.
Nam Phan came into his fight vs. Jimy Hettes as the favorite, but he left with a unanimous-decision loss over three rounds of featherweight action.
Hettes was able to take down and control the former Ultimate Fighter competitor for the majority of the bout, and it would be more than enough to secure the win. Two of the judges awarded Hettes 30-25 scorecards.
For Phan's next fight, he should take on Mark Hominick, a proficient stand-up fighter who was last seen getting stopped quickly by Chan Sung-Jung. It's a fan-friendly matchup that promises to showcase the best of both fighters.
Alexander Gustafsson was 16 years younger than his opponent, Vladimir Matyushenko, but the fast-rising light-heavyweight had little trouble in stopping the MMA veteran in the first round of their bout.
Since returning to the UFC, Matyushenko had obtained four victories and lost twice to Jon Jones and Gustafsson.
It's hard to say the loss is that big of a setback when his losses have come against highly touted opponents.Jones went on to become the UFC light heavyweight champion while dominating the best of his division.
A fight vs. Kyle Kingsbury, who recently had his four-fight win streak snapped against Stephan Bonnar, could be a bout to get him back on the winning track.
Many had Jon Fitch ranked No. 2 in the welterweight division before heading into his bout with Johny Hendricks, and his title dreams came crashing down when he was knocked out with a left hand just 12 seconds into the very first round.
It's a setback for Fitch, but it might be an important fight in helping him reevaluate his career to put on better fights than most fans have come to know him for.
Either that, or it will make him super-extra cautious against dangerous opponents.
Many are anticipating him to be put on an undercard his next time out, but a fight vs. the loser of the upcoming Nick Diaz-Carlos Condit bout could be next. If the UFC doesn't put him on a main card again and wants to match him up with someone on the undercard, a fight with someone like Josh Neer or Duane Ludwig could happen.
Donald Cerrone brought a lot of emotion to the cage to take on Nate Diaz, and it worked against him, as Diaz soundly out-boxed and beat him to win a unanimous decision with the scores 30-27, 30-27 and 29-28.
Cerrone seemed to be fighting with his heart for most of the fight, and he had to use every bit of it to survive being out-landed 4-to-1 over 15 minutes.
With the loss, Cerrone ends 2011 with four victories and one defeat. All of them came inside the Octagon.
A fight against the loser of the upcoming Joe Lauzon-Anthony Pettis bout would be a lightweight matchup fans don't want to miss.
Brock Lesnar accomplished a lot more than many expected him to with less than 10 fights under his belt.
In those fights, he won, defended and lost the UFC heavyweight championship. His victories included those over Randy Couture, Frank Mir and Shane Carwin.
With the loss vs. Alistair Overeem behind him, the 34-year-old will focus his attention elsewhere, as he has decided to retire and officially announced it in the post-fight interview.