Oasis frontman Liam Gallagher had already hyped up a lively crowd with a musical interlude before the main event – and Dubois proved a Rock ‘N’ Roll Star.
Despite being champion and going against tradition, he walked first to the ring to jeers as fireworks shot up above the iconic Wembley arches.
A sea of camera phones further illuminated the national stadium when fan-favourite Joshua – his eyes firmly focused on the ring – entered to a medley which started with the Godfather theme and ended with ‘War’ from Rocky IV.
Only four of their 49 combined wins had gone the distance and the expected early knockdown came in the first round from underdog Dubois when he connected with a superb overhand right in the closing seconds.
Joshua slumped to the canvas and had still not recovered in the second. Dubois did not take a backward step, stalking his opponent around the ring and finding success with his rod-like jab.
Perhaps Joshua was still haunted by those sparring stories from several years ago when Dubois reportedly rocked him.
The 2012 Olympic gold medallist was reeling in the third as a pumped-up Dubois whipped in a left hook and Joshua appeared to touch the floor with his glove. It was not counted as a knockdown, but Dubois continued the assault until Joshua was floored again.
He was dropped twice in the third – the second ruled a slip but the writing was clearly on the wall. Unified champion Usyk and Tyson Fury, who contest a rematch in December, watched on from ringside, scarcely believing how the fight had unfolded.
The chants of “AJ, AJ” had quietened.
After a closer fourth round, Joshua, for the first time in the fight, landed a clean punch in the fifth, only for it to spur Dubois into action.
A counter right-hand, a punch that will live forever in the memory of Dubois and all those in attendance, sent Joshua down for the final time.
The former poster boy of British boxing was left scrambling across the floor, desperately trying to get up, but unable to beat the count.