Anthony Joshua produced the best performance of his career on Saturday, dropping the former unified world champion in the fifth round, before being put down – for the first time in his 19-fight career – in the sixth.
Joshua delivered the clinical blows on his Ukrainian opponent in the 11th round.
The Briton landed a brutal uppercut which gave him the platform to send Klitschko down with an immediate flurry.
The former champion stood, but was dropped by a left hook again moments later, then stood again, only for referee David Fields to save him when pinned against the ropes.
Joshua threw his arms into the air as roars rolled down the Wembley tiers. He had come through his stiffest test to date, while Klitschko too had showed he remains competitive at world level, even at 41.
He will regret not finishing the job when he floored Joshua and appeared tantalisingly close to reclaiming two of the titles he lost in his last fight against Tyson Fury in 2015.
At the time of the stoppage, Joshua was up 96-93 and 95-93 on two cards, with Klitschko leading 95-93 on the other.
A post-war record 90,000 fans watched the bout at the British national stadium, Wembley while another pockets of crowd gathered at the ancestral home of the Nigerian born Anthony Oluwafemi Olaseni Joshua in Sagamu, Ogun state, Nigeria and watched the epic fight on television.