[9] On 4 November 2017, he gained a disqualification (DQ) win over Tayar Mehmed at the Bowlers Exhibition Centre in Manchester.

After being repeatedly warned for spitting out his gum-shield, referee Darren Sarginson disqualified Mehmed in the fifth-round.

[10][11] In his sixteenth fight, with a record of 15–0 (12 KO), he faced Emmanuel Anim for the vacant Commonwealth light-heavyweight title on 12 October 2019, at the First Direct Arena, Leeds.

In a fight which saw Arthur go beyond six rounds for the first time in his professional career,[12] he dropped his opponent in the fourth round en route to a unanimous decision victory, with the judges' scorecards reading 117–111, 117–110 and 115–113.

[13] Arthur was scheduled to defend his title against Anthony Yarde on 11 April 2020,[14][deprecated source] however due to the COVID-19 pandemic, the fight was rescheduled to 5 December 2020.