Great boxing fights: Anthony Joshua defeats Wladimir Klitschko at Wembley on April 29, 2017

Scroll down for round-by-round report

Making the third defence of his IBF title, he also became the WBA champion after recovering from the first knockdown of his career to impressively win at Wembley Stadium.

In only his 19th professional match-up and in front of an estimated 90,000-strong crowd, a post-war record for a fight in the UK, he was at severe risk of his first ever defeat after hitting the canvas in the sixth following a huge right hand.

A period of survival followed before, as Joshua recovered his confidence and ambition in the final rounds, he secured two further knockdowns and forced referee David Fields to intervene with Klitschko unable to defend himself from another heavy barrage.

Since winning his gold medal at the London Olympics in 2012, Joshua has long been seen as the fighter to revive the heavyweight division that had become so predictable during the Klitschkos' lengthy reign.

The biggest questions about his ability to do so focused on whether he truly justified that billing - if he was more than just a promising athlete - and whether the timing was right to test him against perhaps the world's best.

After the competitive opening rounds when each fighter landed promising punches, it was in the fifth when there seemed little that could stop the younger man.

He rocked Klitschko with a big left hand, but after leaving him clinging on and celebrating when sending him to the canvas with a powerful barrage, Joshua became reckless, and swallowed a left hook that now left him fighting to survive.

Suddenly Joshua was the stationary target, looking tired and vulnerable, and from the sixth round Klitschko exerted his class by repeatedly landing with the jab before throwing a huge right hand then left hook that sent Joshua down for the first time in his career.

Returning to his feet after an eight count, he simply looked out of his depth, uncertain about how to respond and remaining that way until the end of the seventh.

Entering the eighth for the first the time and clearly tired, Joshua fought with more ambition, but was learning on the job while his experienced challenger remained composed, jabbing and succeeding with another right.

Only in the ninth did Joshua once again look the more positive of the two, but with the concern that Klitschko was using his experience to patiently wear him down while pursuing the upset.

The Ukrainian followed that with another big right in the 10th, when the 27-year-old Joshua - like so many of Klitschko's opponents - again looked short of ideas.

With a 65th win of a decorated career again looking likely, Joshua suddenly and dramatically changed the course of the fight and his career by securing victory in the way so many heavyweight greats do.

He rocked Klitschko with a huge right uppercut as further punches secured the knockdown, again sent him to the canvas with another hurtful barrage, and - with Klitschko caught on the ropes - forced America's Fields to intervene after two minutes and 25 seconds.

Klitschko never fought again, meaning his record of 18 title defences would never surpass Joe Louis' 25 but there is little question he will be remembered as one of the finest ever heavyweights.

His retired older brother Vitali also left a big impression on the division, in which Joshua is still enjoying success alongside British rival Tyson Fury despite one shock 'blip' against Andy Ruiz which he later redeemed himself from in a rematch last year.

"A massive shout out to Wladimir Klitschko for taking part, I'm not going to say too much, in terms of the boxing hall of fame, he's a role model in and out of the ring," said Joshua.

"Boxing is about character, as I said from the get go it will be a boxing classic, find what you believe in and give it a go.

"I came out and I won, I didn't go into the slugfest, I came back and fought my heart out . (Tyson) Fury where you at, baby?

"I love fighting. Tyson Fury, I know he's been talking, I want to give 90,000 a chance, I just want to fight. (Evander) Holyfield, Roy Jones Jnr, you're all my inspirations. Thank you for coming out to a beautiful night of boxing."

Klitschko was graceful in defeat and said the best man won on the night.

He said: "London, I hope you enjoyed the fight, he beat me at his best, the best man won tonight.

"Two gentleman fought each other, Anthony won tonight, I (was) waiting to give but all the respect to you guys, thank you.

"I wish I could raise my hands but congratulations to Anthony."

ROUND-BY-ROUND REPORT

ROUND 1: Both men were intent on finding their range with the jab for much of the round. Joshua had the edge in speed. Klitschko was content to control the middle of the ring while Joshua searched for opportunities to counter and managed to land a right hand - the most telling punch of the round. Joshua 10 Klitschko 9

ROUND 2: Klitschko immediately sprang out of the corner and landed a swift right. But Joshua answered with a lead right which caught the attention of the Ukrainian. The 41-year-old was coming forward, showing more intent than in his last defeat to Tyson Fury. Close but Joshua takes it on activity. Joshua 20 Klitschko 18

ROUND 3: Joshua began to impose himself on his opponent and went on the front foot as an uppercut and hook pushed Klitschko backwards. Klitschko continued to paw out and jab feints but with nothing coming behind it. Joshua 30 Klitschko 27

ROUND 4: A right-hand-left-hook combination from Joshua brought the crowd to its feet, although it did not land cleanly. A looping right landed on the ear of Klitschko. The Ukrainian landed a nice left-right combination but Joshua looked the better of the two. Joshua 40 Klitschko 36

ROUND 5: Joshua came out all guns blazing and stunned Klitschko with a looping left hook during a furious melee and dropped the former heavyweight champion. Joshua, though, punches himself out as Klitschko, who seemed to suffer a cut to his left eye, used all of his experience to weather the storm. With Joshua gasping for air, Klitschko went on the offensive and finished the round strong. Joshua 50 Klitschko 44

ROUND 6: Klitschko smelled blood and buckled the legs of Joshua with a powerful right hand which put the younger fighter on the canvas for the first time in his career. Joshua bravely got up but Klitschko took his time and landed cleanly throughout. Joshua 58 Klitschko 54

ROUND 7: Respecting the power of Joshua, Klitschko steadily stays on the front foot and pushed the wounded IBF heavyweight champion back. Joshua gamely stayed out of range but Klitschko looked the fresher of the two. Joshua 67 Klitschko 64

ROUND 8: Joshua entered unknown territory in the eighth and still looked exhausted. The Briton threw a lunging right as Klitschko took his time and waited for the opportunity to land the knockout blow that could have seen him reclaim the heavyweight championship. Joshua 76 Klitschko 74

ROUND 9: Klitschko continued to control the tempo, not wasting any punches but Joshua, despite suffering from the knockdown in round six, was still dangerous and landed a left hook. Joshua 85 Klitschko 84

ROUND 10: Joshua slowly regained his senses and went on the offensive, with both men looking visibly tired. A swift right-hand counter caught the attention of Joshua late in the round as Klitschko stayed in command. Joshua 94 Klitschko 94

ROUND 11: A stinging right hand from Joshua momentarily buckled the legs of Klitschko as the 27-year-old mounted a comeback. Joshua sensationally found a surge and landed a beautiful uppercut followed by a barrage of punches to put the Ukrainian down for the second time in the fight. Klitschko showed heart to get back up but went down again after another Joshua onslaught. Klitschko, somehow, got up but Joshua jumped all over the former champion and the referee stopped the fight. Joshua wins by 11th-round TKO.