 The next challenge for Santiago was the Strikeforce Middleweight tournament on November 16, 2007.Competing in the tournament as the underdog, Santiago won the Grand Prix by defeating Sean Salmon and Trevor Prangley on the same night.Continuing on his path of success, Santiago became Middleweight Champion, by defeating Yuki Sasaki, Logan Clark, Siyar Bahadurzada, and Kazuhiro Nakamura.