Career
He is known for his aggressive and at times sloppy fighting style. As of 2 November 2015, he is ranked the #11 light heavyweight in the world by GLORY. Duut started kickboxing when he was 10 years old after being bullied at school. After a fight at school with an older boy his father made him to go back and fight again.
According to him and his father he knocked the guy unconscious.
His father send him to kickboxing classes after that. Duut fights out of Mejiro Gym since his early teens.
On March 23, 2013 he fought Dustin Jacoby at Glory 5: London, winning by TKO in the first round. On April 20, 2013 he defeated Australian Steve McKinnon by unanimous decision at Glory 7: Milan.
Duut was part of the Light Heavyweight Tournament Glory 9: New York - 2013 95kg Slam on June 22, 2013 losing in the first match to Tyrone Spong.
Duut created an upset by dropping tournament favourite Spong in the first found, but was KO"d seconds later. On October 12, 2013 he fought at Glory 11: Chicago where he lost in round 1 by TKO due to arm injury to Glory contender Danyo Ilunga. Duut lost his third fight in a row on March 8, 2014 at Glory 14: Zagreb by KO in round 1 to Igor Jurković.