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.