Chelli made his pro-debut at York Hall in London on 24 February 2017, stopping Jacob Lucas in the third of their scheduled four-round encounter.
[3] He won his first professional title in his eighth fight, claiming the vacant Southern Area super-middleweight crown with a unanimous decision victory over Jimmy Smith at Wembley Arena on 27 April 2019.
[4][5] On 10 November 2020, Chelli defeated Vladimir Georgiev by unanimous decision and Mike McGoldrick via a second round stoppage at BT Sport Studio in Stratford to win the Boxxer VII tournament and secure a two-year contract with the promotional company.
[13] Chelli challenged British and Commonwealth super-middleweight champion Jack Cullen at Liverpool Arena on 20 January 2024, winning the bout by unanimous decision.
[16][17] Chelli has a degree in business, management and marketing from the University of Surrey and, after gaining a teaching qualification, worked as a substitute teacher during the COVID-19 lockdowns in 2020.