The Cameroonian fighter suffered a knockout defeat at the hands of the former world heavyweight champion in the second round.
Despite his commendable boxing debut against Tyson Fury last year, the mixed martial artist fell short against his more seasoned Nigerian-British opponent.
The 37-year-old’s defeat by second-round knockout followed a first-round knockdown by Joshua, from which Ngannou struggled to recover.
A powerful right hand from Joshua prompted the referee to halt the fight in the second round.
“Apologies to everyone; I feel I let you down,” Ngannou wrote on his X account.
“Today was a bad day in the office but tomorrow will be another day. Thank you all for the love,” he added.