There was no doubt about Zhilei Zhang’s knockout of Joe Joyce in their rematch Saturday night.

The powerful Chinese southpaw blasted Joyce with a perfectly executed right hook that abruptly ended their WBO interim heavyweight championship rematch late in the third round at OVO Arena Wembley in London. Joyce got up in time, but referee Steve Gray determined that the staggered challenger shouldn’t continue and waved an end to their 12-round fight with no time remaining in the third round.

The 40-year-old Zhang (26-1-1, 21 KOs), who caused the first knockdown of Joyce’s pro career, retained the WBO interim crown he won from Joyce on April 15. His second loss to Zhang in the past five months was a career-crushing setback for the 38-year-old Joyce (15-2, 14 KOs), who exercised his contractual right to their immediate rematch.

“I feel very happy,” Zhang said through his translator. “Like I said before the fight, it’s gonna end before the first fight. I did it. But Joe, hell of a fighter, respect to him. I like him. I respect him. Everybody please cheer for him.”

Joyce weighed in for their rematch at a career-high 281.2 pounds, 25.2 pounds heavier than he was for their first fight, in hopes of absorbing Zhang’s power more effectively. The extra weight made the 6-foot-6 Joyce even slower and helped Zhang repeatedly land left hands and right hooks on the defensively deficient 2016 Olympic silver medalist.

The 6-foot-6, 287-pound Zhang’s performance cemented him as a top heavyweight in the twilight of his late-blossoming career. He also maintained his position as the WBO’s mandatory challenger for one of Oleksandr Usyk’s titles.

“This is what we’re here for, man,” Zhang said. “We’re professional fighters. We come here to entertain the crowd. We did it. I hope everybody enjoyed my performance.”

Zhang upset Joyce by sixth-round technical knockout in their first fight April 15 at Copper Box Arena in London.

Swelling surrounding Joyce’s right eye caused referee Howard Foster to stop the action at 1:23 of the sixth round. A British Boxing Board of Control physician recommended that Foster stop the bout because he didn’t think Joyce could see out of his right eye.

Joyce, who entered the ring as a 9-1 favorite five months ago, was ahead on the scorecard of English judge Phil Edwards by one point, 48-47, through five rounds. Two American judges – Wisconsin’s Mike Fitzgerald and Florida’s Efrain Lebron – had Zhang in front by the same score, 48-47, entering the sixth round.

Joyce told BoxingScene.com recently that he thought he could’ve continued, but he didn’t protest Foster’s decision the night of April 15.

Before the knockout shot Saturday night, Zhang rocked Joyce with a left hand when there was a little less than 1:20 on the clock in the third round. A right hook by Zhang knocked Joyce backward a little less than a minute into the third round.

Zhang opened up on Joyce toward the end of the second round, when the southpaw landed a straight left and a right hook that knocked Joyce off balance. Gray warned Joyce with about 30 seconds to go in the second round for hitting Zhang low.

Zhang rocked Joyce with a straight left hand and then a right hook a few seconds after the midway mark of the second round. Zhang landed two straight left hands in less than 10 seconds during the opening minute of the second round.

Neither fighter landed a significant punch during the first round. Joyce defended himself well, particularly by keeping his right hand held high to protect his right eye, and he didn’t open up to throw punches at Zhang in the opening three minutes.

Keith Idec is a senior writer/columnist for BoxingScene.com. He can be reached on Twitter @Idecboxing.