[6] He beat Pacôme Assi by second-round KO at the SUPERKOMBAT World Grand Prix 2013 Final Elimination in Ploiești,[7][8] but lost to the eventual champion Frank Muñoz by unanimous decision in the semi-finals.
[9] He defeated Thomas Vanneste at SUPERKOMBAT World Grand Prix III 2014 in Constanța, Romania on June 21, 2014.
[13] He was scheduled to face Guto Inocente in a co-headliner at Glory 37: Los Angeles[14] Innocente won the fight by an extra round decision.
He knocked out Mohamed Abdallah after just 48 seconds in the semifinals, and won a unanimous decision against Anderson Silva in the finals.
[18] Marshall won three of his next five fights, defeating Antonio Dvorak,[19] Daniel Škvor[20] and Jahfarr Wilnis,[21] but losing to Jamal Ben Saddik and Benjamin Adegbuyi.