for the Strikeforce Lightweight Championship took place at Strikeforce: Barnett vs. Cormier on May 19, 2012, with Thomson losing the fight via split decision. Return to the UFC Following the dissolution of Strikeforce in January 2013, Thomson returned to the UFC and faced Nate Diaz on April 20, 2013 at UFC on Fox 7. He won the fight via TKO (head kick and punches), becoming the first of only two fighters to date to finish Diaz by way of strikes. The win also earned him his first Knockout of the Night bonus award. Thomson was expected to face current UFC Lightweight Champion Anthony Pettis on December 14, 2013 at UFC on Fox 9, replacing an injured T. J. Grant, However, the bout was cancelled after Pettis pulled out of the bout citing a knee injury. Thomson faced Benson Henderson on January 25, 2014 in the main event at UFC on Fox 10. Henderson defeated Thomson via split decision. Many media outlets and observers were split on who they thought should have been declared the winner. Thomson had one more takedown (5 to 4) and was able to secure Henderson's back on multiple occasions, while Henderson was able to significantly outstrike Thomson (114 to 33) over the duration of the bout and was credited with the bout's only submission attempt. During the first round Thomson broke the thumb on his right hand, contributing to his inability to punch with much effectiveness. Disappointed in the result of the Henderson bout, Thomson indicated in the post-fight press conference, that he may be "done" with the UFC or fighting. Thomson was expected to face Michael Johnson on July 26, 2014 at UFC on Fox 12. However, on July 11, Johnson pulled out of the bout due to injury and was replaced by Bobby Green. Thomson lost the bout via split decision. Thomson was expected to face Gilbert Burns on March 21, 2015 at UFC Fight Night 62. However, on February 26, Thomson pulled out of the fight with an undisclosed injury, while Burns remained on the card against a replacement. Thomson faced Tony Ferguson at UFC Fight Night: Mir vs. Duffee on July 15, 2015. He lost the fight via unanimous decision. Thomson's contract ended after his bout with Ferguson and he opted not to re-sign with the UFC. Bellator MMA On August 11, 2015, Thomson signed a multi-fight contract with Bellator MMA. He