 This was the last event held by WEC before it was acquired by Zuffa, LLC, then-parent company of the UFC.Diaz was a contestant on "The Ultimate Fighter 5", which exclusively featured lightweights, fighting on Jens Pulver's team.In the preliminary round, Diaz defeated Rob Emerson by submission; in the quarterfinals he defeated fellow Team Pulver teammate Corey Hill via triangle choke submission in the first round.