Joshua was outworked to lose a split decision at Jeddah’s King Abdullah Sports City Arena with scores of 113-115, 115-113, 116-112 conforming that he is now a peripheral figure among the heavyweight division’s elite.
But while Usyk retained the WBA, IBF and WBO titles to set up the prospect of a unification clash with Tyson Fury, he was hurt on several occasions by an underdog who was transformed from the first meeting at Tottenham Hotspur Stadium.
Joshua lacked the gas or the class to reclaim his belts, but he went out on his shield in a thriller that atoned for his passive display in London nearly a year ago.
For a second time Usyk was operating on a different level, his movement and ringcraft keeping him away from the Briton’s most dangerous shots, while his accuracy and volume of work swept him to place him in charge on the scorecards.
Joshua stunned many observers after the fight as he grabbed Usyk’s world title belts, threw them out of the ring and then grabbed the microphone to start an expletive-laden rant.
"If you knew my story, you'd understand the passion,” said an emotional Joshua in the ring. “I’m not an amateur boxer. I was going to jail and I got bail and I started training. If I got sentenced, I wouldn't be able to fight.
"It shows the passion we put into this. For this guy to beat me tonight, it shows the levels of hard work he must have put in so please give him a round of applause as heavyweight champion of world.
"They said that I’m not a 12-round fighter. I ain’t 14 stone, I’m 18 stone, I'm heavy. It’s hard work. This guy here is phenomenal."
Joshua’s raw emotion was also on display in his post-fight press conference, as he broke down in tears.
Former world champion Carl Froch described Joshua’s behaviour as strange, as he questioned whether he will continue in boxing.
"He got the mic, he stole Usyk's moment but let's not go too mad. He didn't say anything that would have offended anybody too much," said Froch.
"He was just trying to speak off the cuff. He put his heart on his sleeve but he did steal Usyk's moment and it was a bit strange.
"I didn't like the way the belts got thrown. It was a great boxing match, I thought it was a great performance. But that highlights his passion - how much it meant to him and how much he wanted it."