5. Mauricio Rua
When Shogun arrived in the UFC in 2007 there was quite a bit of buzz around him. He had won the Pride Middleweight Grand Prix in 2005 and had defeated names like Alistair Overeem, Rampage Jackson and Kevin Randleman. He was expected to be just as dominant in the UFC.
Rua dropped his first UFC bout to Forrest Griffin, but would win his next two against Mark Coleman (avenged a loss in Pride to him) and Chuck Liddell. This earned Rua a title shot against then-undefeated champion Lyoto Machida. The whole word, including Machida, reacted with shock when a controversial decision in the title fight allowed Machida to keep the belt after their UFC 104 bout.
The UFC immediately scheduled a rematch as a result of the judging decision, and this time Shogun made things easier for everyone by knocking Machida out in the 1st round.
Since that title win Shogun has only ever shown mere glimpses of what he used to be however. He dropped the title in his first defence to Jon Jones, and has a 5W-6L record since. Shogun has dropped 2 fight of the nights to Dan Henderson, lost to Chael Sonnen, Alexander Gustafsson and Ovince Saint Preux since winning the title.
