by unanimous decision. Thomson would go on to win his next six fights, including victories over Duane Ludwig and Nam Phan earning him another shot at the Strikeforce Lightweight Championship. On June 27, 2008, he defeated Gilbert Melendez by unanimous decision at Strikeforce: Melendez vs. Thomson to become the new Strikeforce Lightweight Champion. On November 21, 2008, Thomson was scheduled to make his first title defense in a rematch against Yves Edwards at Strikeforce: Destruction but had to pull out after tearing ligaments in his toe. Duane Ludwig was selected to take Thomson's place on the card. On April 11, 2009, Thomson was scheduled to make his first title defense in a rematch against Gilbert Melendez at Strikeforce's debut on the Showtime Network, but had to pull out after breaking his ankle while training on April 1, 2009. Rodrigo Damm was selected to take Thomson's place on the card. On August 15, 2009, Thomson was scheduled to unify his title with the newly crowned Strikeforce Interim Lightweight Champion Gilbert Melendez at Strikeforce: Carano vs. Cyborg, but suffered a broken leg in training. Mitsuhiro Ishida was selected to take Thomson's place against Melendez. On December 19, 2009 at Strikeforce: Evolution, Thomson fought Gilbert Melendez for the Lightweight Championship. Thomson would lose the fight by unanimous decision, but the fight would see both fighters put it all on the line in what would prove to be a very fast-paced and exciting fight. Thomson fought Pat Healy at Strikeforce: Fedor vs. Werdum and won by rear naked choke late in the 3rd round. After this win, Dave Camarillo granted him his black belt in Guerrilla jiu-jitsu. Thomson broke two ribs during the fight on Healy's very first takedown and fought the rest of the fight very defensively. Thomson fought Gesias Cavalcante on October 9, 2010 at Strikeforce: San Jose where he won a controversial unanimous decision (29–28, 29–28, and 30–27). Thomson's next fight was against Tatsuya Kawajiri under the co-promoted DREAM, K-1 end of year event Dynamite!! 2010. He lost the fight via unanimous decision. Thomson was expected to face promotional newcomer Maximo Blanco at Strikeforce World Grand Prix: Barnett vs. Kharitonov but yet another foot injury forced him out of the bout. Thomson returned in March 2012 to face K. J. Noons at Strikeforce: Tate vs. Rousey. He won the fight via unanimous decision. The trilogy rematch between Thomson and Gilbert Melendez