ANTHONY JOSHUA was walking back to his dressing room, dazed, bedraggled — he could barely see out of his right eye — with sympathetic shouts coming from the crowd of 66,000 who’d just seen British boxing’s national treasure lose his world heavyweight titles again.

Joshua was trying hard not to feel sorry for himself. In fact, he was already plotting how he could defeat Oleksandr Usyk in a rematch.

“When I was walking back through the tunnel, I just said to myself, ‘I’m ready to get back to the gym, I’m ready to just put that work in’,” Joshua said.

“Most people after they’ve finished a fight, it’s like, ‘Yeah, let me go out and have a bit of fun.’ But my mindset is a bit different.”

So, after shaking hands with Usyk and video-calling the new champ’s kids back in Ukraine, Joshua got his team to put on a tape of the fight and watched it with two people close to him — Tony Bellew and Derek Chisora — who have also lost to Usyk over the past three years.

“This isn’t just one fight and then I’m done,” Joshua said. “I’ve got an opportunity to go back to the drawing board.”

The video will have been a tough watch. Befuddled by fighting a southpaw for only the second time, Joshua was given a lesson in movement and punching speed by an undefeated 34-year-old opponent who demolished all comers in the cruiserweight division and — after just three fights at heavyweight — already owns three of the four major belts in boxing’s blue riband category.

To Joshua’s promoter, Eddie Hearn, Usyk is the second best pound-for-pound fighter in boxing.

“Anthony could have swerved that fight easy. Maybe we should have,” Hearn said. “But that’s not really what he’s about.

“You’ve got people who will take easy options, and you’ve got people who will choose to fight everybody. And the latter is AJ.”

So, Joshua will “100 per cent, 110 per cent” trigger the rematch clause that was part of the deal.

Hearn said it will take place in February or March, hopefully in Britain and almost certainly not in Kiev — the preferred location for Usyk despite his fearsome reputation as a road fighter.

Joshua’s coach, Rob McCracken, think he knows how his man can close the gap on Usyk and avoid getting in the kind of situation that saw him hanging on the ropes by the end of Saturday’s fight, on the end of a pummelling in his own backyard. He surely would have gone down had the final bell not sounded.

“You’ve got to apply pressure behind your jab and your right hand, keep him off-balance and put your shots together when you get there,” McCracken said.

Easier said than done.

Usyk will start as favourite in the rematch — Hearn said that, and Joshua didn’t disagree — and is blessed with such talent and pedigree that he’ll be confident of outboxing his fellow Olympic gold medallist from 2012 once again.

It was some performance, in only his third heavyweight fight, in such a fevered atmosphere and against a two-time world champion.

By the end, he was bullying the younger Joshua — a man with a distinct advantage in height, weight and reach — and won comprehensively on all three of the judges’ scorecards.

“It is the biggest fight in my career, but it wasn’t the hardest one. That is ahead of us,” Usyk said.

Before that — and Joshua now has the benefit of a fight against the slippery and sharp Usyk in the memory bank — Usyk wants to go home and “live” a simple life for a while.

“I want to take my kids to school, I want to plant trees, I want to water apple trees, I want to see my wife more often,” he said.

He’ll return home to a hero’s reception — Usyk is already a big deal in Ukraine — and put the WBA, WBO and IBF heavyweight titles alongside his heavyweight gold medal from the 2012 Olympics, the piece of hardware he still treasures more than any other.

And Joshua? The popular Londoner just went through his most chastening experience in the ring, outclassed rather than surprised like he was in the stunning loss to Andy Ruiz Jr in 2019.

For that reason, the recovery process will be different, and he’ll have to reassess his approach. That might also mean looking at his ring walk.

Whereas Usyk was all business on his way to the middle, Joshua might have been too relaxed, high-fiving fans and even cutting away to hug an old face from his boyhood boxing club.

It’s all part of the Joshua Show — he continues to sell out big venues, the latest being Tottenham Hotspur Stadium — but that has been blown off course, along with the all-English narrative of a fight with WBC champion Tyson Fury to be undisputed champion.

It’s not over, though. Joshua is only 31 and is too good — and lucrative — a fighter for Hearn to give up on.

“Maybe AJ gave (Usyk) too much respect, particularly in the early part of the fight,” Hearn said.

“I don’t know if he (Usyk) can be much better. I hope he can’t … I think he boxed the perfect fight. Can he do it again? Maybe he can raise his game, but maybe he can’t box to that level again. AJ will, I promise you, be much, much better than that in the rematch.”