Deontay Wilder uncorked a right hand, only to lose the exchange as the former heavyweight champion was spun around in a daze.
Zhilei Zhang's own right hand met its mark first, and Wilder was now defenseless. Zhang (27-2-1, 21 KOs) capitalized swiftly: he sprinted and unloaded another right hand that sent Wilder crashing to the canvas.
The American somehow beat the referee's count but was in no shape to continue as the bout was waved off in Round 5 Saturday night in Riyadh, Saudi Arabia. And with his fourth loss in five fights, Wilder's latest setback may have signaled the end of his career.
Wilder (43-4-1, 42 KOs) was feared for his dangerous right hand during his long title run, but at 38 years old, no longer possesses the tenacity or willingness to let his best weapon go. And without the ability to unleash his money punch, Wilder is just another heavyweight.
Before his latest loss -- his third by KO -- Wilder said if he was unsuccessful, "this could be the final goodbye, the farewell of Deontay Wilder."
If it's indeed the end, Wilder will be remembered as one of the most dangerous punchers in the history of boxing's glamor division. The superfight with Anthony Joshua never materialized, and that's a shame, but Wilder still delivered an epic heavyweight championship trilogy with Tyson Fury.
Wilder didn't defeat Fury in any of those three fights, but he did score four knockdowns across the first and third meeting. And that final bout was named ESPN's 2021 Fight of the Year and KO of the Year.
Despite his 6-foot-7 frame, Wilder was routinely outweighed by his opponents. And that was again the case Saturday as Wilder weighed 214.6 pounds, 68.2 less than Zhang, who was 282.8. (Zhang won a silver medal as a super heavyweight at the 2008 Olympic Games in Beijing while Wilder claimed bronze in the heavyweight division.)
Wilder was never the most polished fighter, but his wicked right hand usually bailed him out. But inactivity, age and, perhaps most of all, that grueling Fury trilogy seemed to sap Wilder of his best, even if his fighting spirit lived on.
Wilder showed tremendous courage to make it to his feet Saturday -- as he did in the second and third fights with Fury -- but his time as a title contender is clearly over. There were plans to match him with undefeated contender Jared Anderson on Aug. 3 on the Terence Crawford-Israil Madrimov Riyadh Season undercard, but that potential bout surely won't happen now.
While Anderson seeks a new opponent, Zhang has reignited his career at age 41 following an upset loss to former heavyweight champion Joseph Parker, who routed Wilder in December.
Zhang floored Parker twice in that March meeting but still lost on the cards. Against Wilder, Zhang was far sharper and active. And he's still seeking his first opportunity to become the first heavyweight champion from China.
Zhang, who entered the bout rated No. 6 by ESPN at heavyweight, should now have plenty of options in the resurgent heavyweight division. While Oleksandr Usyk heads toward a championship rematch with Fury on Dec. 21 in Riyadh, Zhang could perhaps move on to fight Anderson.
Or he could look to a rematch with Parker, who was ringside for the fight. Another option for Zhang: a Sept. 21 fight with Anthony Joshua at Wembley Stadium, though that opportunity could go to Daniel Dubois, who stopped Filip Hrgovic on the undercard.
Whomever Zhang meets next, his career is as relevant as ever following his biggest win yet. Wilder's own career, meanwhile, may be over.