When Anderson Silva steps in the cage this weekend against Chris Weidman, he will look to keep his seven-year title reign intact. Though a Weidman win would hardly be the most shocking in the history of UFC championship fights, it would be an improbable one, considering Silva is (probably) the greatest fighter in the history of the sport.
But Weidman wouldn't be the first to pick up an unlikely win against a dominant fighter and champion.
Other champions have set foot in the cage with the odds in their favor, only to witness the belt change hands at the end of the night. So here are the top five most improbable title wins in UFC history.
Note: This list will include only upsets which occurred during the Zuffa era, meaning Maurice Smith defeating Mark Coleman is out of the picture.