As an amateur kickboxer Thompson amassed 16 titles and finished his career with a record of 37 wins, 18 by knockout and no losses.

[20] On December 14, 2004 Thompson traveled to Montreal, Canada to face Eric Boudreau at "La renaissance du Kickboxing" event.

[21] On May 21, 2005 Thompson rematched Kadir Kadri at Martial Arts May-Hem 05 in Greenville, South Carolina.

[22] On September 3, 2005 Thompson faced Freddie Espiricueta at the APEX – Undisputed event in Montreal, Canada.

He went undefeated during that year earning wins over opponents such as Antoine McRae, Armin Mrkanovic, James DeCore, Tim Williams and Carlos Tearney.

[25][26] Thompson lost the bout by technical knockout due to a knee injury he suffered that left him unable to continue.

Thompson was expected to face Justin Edwards on February 4, 2012, at UFC 143, replacing an injured Mike Stumpf.

[45] Despite knocking Côté down in the third round and almost finishing the bout, Thompson ultimately won the fight via unanimous decision.

[47] However, Thompson pulled out of the fight on January 30, citing a rib injury, and was replaced by former UFC Lightweight Champion Benson Henderson.

[52] However, Magny was tabbed as an injury replacement for Matt Brown and instead faced Kelvin Gastelum on November 21, 2015, at The Ultimate Fighter Latin America 2 Finale.

[53] In turn, Thompson was removed from the card and rebooked to face former champion Johny Hendricks on February 6, 2016, at UFC Fight Night 82.

[66] As the first bout of his new multi-fight contract, Thompson faced Darren Till on May 27, 2018 at UFC Fight Night 130.

After negotiating with Thompson's team, the bout proceeded at a catchweight, with the stipulation that Till could not weigh more than 188 pounds on the day of the fight.

[72] Despite outstriking Pettis for most of the bout, he lost the fight via knockout in the second round, marking the first time that Thompson had been stopped in MMA or kickboxing competition.

[79] Thompson faced Gilbert Burns on July 10, 2021 at UFC 264[80] He lost the fight via unanimous decision.

[81] As the first bout of his new six-fight contract, Thompson faced Belal Muhammad on December 18, 2021 at UFC Fight Night: Lewis vs.

[82][83] He lost via unanimous decision after ending up in bottom position on the ground for a large portion of each round.

This karate background is evident in the stance he adopts, as his feet stand far apart and he sits wide with his hands low.

His footwork is described as "hopping back and forth", like other practitioners do such as Conor McGregor, Robert Whittaker and Zhang Weili.

The benefits of a very low guard are that your punches and elbows become very hard to predict, and one is better prepared to defend against takedowns.

Thompson is more suited to keeping his hands low than other fighters who adopt more orthodox MMA stances, as he can negate the risk of being hit with a clean shot to the head through his footwork and rapid movement.

[96] In 2022, Thompson made his acting debut as Sensei Morozov in two episodes of season 5 of the Netflix series Cobra Kai.