It was a night to remember for the Ukraine-born fighter, who produced a boxing masterclass inside Tottenham Hotspur's £850 million stadium to become WBA (Super), IBF, WBO, and IBO heavyweight champion.
The unbeaten 34-year-old picked up the victory via unanimous decision, with the judges scoring it 117-112, 116-112 and 115-113 on the scorecards as London 2012 Olympic Gold medalist AJ suffered his second career defeat.
And as he walked past thousands inside the stadium, one fan decided to hurl some choice words towards promoter Eddie Hearn, who decided to turn around and respond to the heckler.
You can see the footage below.
Yesterday at #JoshuaUsyk :eyes:
Fan: "Eddie, you're a p*ssy!"
- Strictly Boxing Fans (@BoxingBritain1) September 26, 2021
Moments after the abuse was aimed towards Hearn, he pointed at the fan and asked "what did you say?" before commenting that the person involved shied away when confronted.
Here's how social media reacted to the incident.
Fair play, too many getting mouthy without consequence these days :joy:
- Ryan McKean (@ryanmckean) September 26, 2021
Fair play to @EddieHearn, I don't agree with everything he does but personal abuse isn't needed from the spectators
- Paul Jones (@PJJones78) September 26, 2021
Just seen his friend lose all his titles and then some so called fan gives it the big one
- Bushy (@bushy_1969) September 26, 2021
Eddie Hearn has since claimed Joshua "will want" an immediate rematch with Usyk as he looks set to trigger the rematch clause.
"It's going to be really difficult because Usyk's confidence will be sky high, but when you get to the level of Anthony Joshua, as we saw after the Ruiz defeat, there's no 10-round comeback fights and warm-ups," Hearn told Sky Sports.
"It's straight back into the fire and he will want to go straight back into that rematch. He will be an underdog in the rematch this time after that tonight, but that's what he does."
Hearn continued, saying: "It was a tough fight, a gruelling fight. He's not quite talking the way you would expect him to talk at the moment. Devastated. He's already talking about training again.
"They want to look at the eye socket. He says it's fine, but a devastating defeat.
"Obviously congratulations to Oleksandr Usyk. What a fighter. He put in a great performance tonight and the better man won."
:speaking_head: "You got beaten by the better man, what are you going to do about it?"
Eddie Hearn reflects on Anthony Joshua's world heavyweight championship defeat to Oleksandr Usyk... pic.twitter.com/R9uhBmCkgm
- Sky Sports Boxing (@SkySportsBoxing) September 26, 2021
Shortly after his loss against the impressive Usyk on Saturday evening, Joshua broke his silence with a social media post.
"Keep positive even if the world's crumbling in front of you," he wrote. "London I love you & thank you each and every time!"
Keep positive even if the world's crumbling in front of you! London I love you & thank you each and every time! pic.twitter.com/GBgF7e5hcm
- Anthony Joshua (@anthonyjoshua) September 25, 2021
Featured Image Credit: MichaelBenson/Twitter