Joshua-Klitschko thriller the greatest fight Wembley has seen | Sean Ingle

Somehow, at the end of this brutal, seesawing, whirligig of a fight, Anthony Joshua still had the energy to stand on the ring apron, revel in the glorious applause of 90,000 people and pound his chest in triumph. The rest of us were left breathless after one of the greatest heavyweight fights in a generation.

Beforehand everyone was playing guessing games about how much Klitschko had left at 41. The last time he had fought, against Tyson Fury in November 2015, he had still looked as sculpted as a Greek statue – but was about as mobile. But here the proud champion, who had been unbeaten in 22 fights over 11 years before facing the fists of Fury, resurfaced with a vengeance. In the end it was age, as much as Joshua, that beat him.

When Michael Buffer announced Joshua’s name Wembley became a carnivorous din. There remains an electricity around a big world heavyweight title fight that is unmatched in sport. The heart quickens. The adrenaline does flipflops. Something about the impending and unpredictable violence concentrates the mind. It is not just the fighters who have to live each moment. We do too. Having so many people in the stadium only magnified it.

The early rounds were close, and after round four the fighters gave each other a mutual nod of appreciation. And then absolute chaos erupted. Round five will go down as one of the great rounds in heavyweight boxing history, along with the first round of Jack Dempsey against Luis Ángel Firpo, round four of George Foreman against Ron Lyle and round 10 of Riddick Bowe against Evander Holyfield – as Klitschko was put down and almost drummed out before coming back to desperately wound Joshua.

When Joshua’s first blow landed in the fifth a shadow of doubt and pain came across the Ukrainian’s face and he was bleeding under one eye but that was only the start of the barrage. Yet Klitschko clung on, absorbed and recovered to drive back his opponent.

For Joshua the crisis was just beginning. He started round six by telling Klitschko: “You can’t hurt me” – only to be felled for the first time in his career by a thudding right. There were many dangerous moments where it looked as if his IBF, WBA and IBO belts was going to be ripped from his waist. Somehow he survived the round, but he was still unsteady on his feet in round seven.

There have been other major heavyweight contests here and at the old stadium. But nothing this big – or epic. In 1963, 35,000 watched Henry Cooper put Cassius Clay on his pants before Clay’s punches turned his face into a dozen red rivers. And 40,000 saw Bruno bludgeoned by Tim Witherspoon during his first world title attempt in 1986 – the same number who were there when he became WBC champion nine years later with a victory over Oliver McCall. But this was far bigger in crowd size and stature.

The pace naturally slowed for both men needed time to breath and they were not the only ones. Frequently their tired bodies would crash into each other at the same time, like rutting stags. But slowly Joshua was finding his legs again, while the energy was draining from Klitschko like a leaking battery. And when a right uppercut swivelled him around in the 11th round he lacked the reflexes to escape.

Joshua was immediately on to him, like a man wanting to fell trees in a hurry. One left hook sent him to the floor. Then another. The stoppage, when it came, was a welcome act of mercy.

“I came out and I won, I didn’t go into the slugfest, I came back and fought my heart out,” said Joshua. “That is what I am about.”

He rightly praised Klitschko too, calling him “a role model in and out of the ring – I have got nothing but respect for him”.

There was also a message for Fury, who is on the comeback trail following a bout of severe depression. “I love fighting,” Joshua said. “I know Tyson Fury has been talking a lot, so I want to give 90,000 people a chance to experience another night of boxing.”

Afterwards there was vague talk of a rematch, with Klitschko insisting: “Of course, I am interested but I need to analyse what the hell happened. I didn’t enjoy the night as much as he did but congratulations to Anthony.”

There is a clause in the contract, which means it could happen but it might be wiser for Klitschko to bow out now, having given everything before falling proudly on his shield and with his reputation higher than for years.

If they do meet again, he will surely know Joshua is likely to be wiser and nastier. It is amazing to think it is just 10 years since he walked into a gym in Barnet to take a keep-fit class and pump iron, and left with a thirst for something altogether more savage. His progress since has rapid, with an Olympic gold followed by a world title. And after this, who would dare suggest his vertiginous ascent is slowing?