Dubois came out swinging from the start. He put Joshua on the canvas in the first round. By the end of the fourth, Joshua had been down two more times. In the fifth, Dubois landed the final blow that ended the fight.
The win puts Dubois in a great spot. He might give Joshua another shot or he could wait to see who wins between Oleksandr Usyk and Tyson Fury in December.
David Price, a former British heavyweight, thinks Dubois will be a handful for anyone. He told YouTube:
"He's going to take them to hell and back isn't he?"
Price thinks Dubois could give Usyk trouble:
"He's like a man possessed, and the Usyk fight, he was in that fight, you could that it wasn't a low blow what he hit him with. and Usyk probably will probably think I could do without fighting him, he'll give him nightmares."
As for Fury, Price says it depends on how the fight goes:
"Tyson Fury, it depends what happens in the fight, but one thing Fury won't be doing is taking as many shots as AJ did that's for sure and the same with Usyk, so it's different when you've got someone in front of you to hit clean it's when you're missing and not landing as much and nicking round here and there it can be a bit different."
Frank Warren, Dubois' promoter, wants to set up a fight with Usyk if he beats Fury again. Warren says he'd make that match "in a heartbeat."
Joshua, a two-time former champ, never got his footing after getting knocked down in the first round. It was a tough night for AJ in front of 98,000 fans at Wembley.
Dubois, who's only 27, will have plenty of options after this win. He showed he's got the power to hang with anyone in the division.
The boxing world will be watching to see what 'DDD' does next. One thing's for sure - he's put everyone on notice with this knockout win.