[3] Buatsi started his early boxing career at the South Norwood and Victory club, Charnwood Road, Crystal Palace, London, England.

On 23 March 2019, Buatsi defeated Liam Conroy via technical knockout in round three to claim the vacant British light-heavyweight title at the Copper Box Arena in London, England.

[6][7] In his US debut, on the Anthony Joshua vs. Andy Ruiz Jr. undercard at Madison Square Garden, Buatsi defeated Mexican veteran and former title challenger Marco Antonio Peribán within four rounds.

[9] On 15 May 2021, Buatsi fought Frenchman Daniel Dos Santos at the AO Arena in Manchester, winning by devastating knockout with a well-timed right hand in the fourth round.

[10] Buatsi followed this up by beating Ričards Bolotņiks with an eleventh round knock out as the main event on the final instalment of Matchroom Boxing's Fight Camp series.

[12] Buatsi won the British and Commonwealth light-heavyweight titles with a unanimous decision win over defending champion Dan Azeez at Wembley Arena on 3 February 2024.