The 33-year-old American extended his perfect career record to 32 wins from 32 in an impressive performance, albeit with a controversial ending, at the Mandalay Bay Hotel and Casino in Las Vegas.
Ward won the pair’s first meeting last November via a unanimous but tight decision, with Kovalev aggrieved at the result having knocked Ward down in round two, and the rematch was eagerly anticipated.
Again the Russian started stronger, with Ward firing off enough counter-shots to keep himself in the fight but looking weary between rounds.
The momentum began to shift the American’s way as the fight reached halfway, though, with both fighters landing some fierce shots in a more open and aggressive encounter than their first bout.
And after wobbling Kovalev midway through the eighth round with a straight right hand, Ward finished the job with a series of powerful body shots – albeit with a suspicion of low blows.
And Kovalev was clearly not happy with the stoppage.
“It was a low blow, again another one,” said Kovalev.
“We are boxers. I could still continue. Why stop the fight?”
Ward added: “He’s a great fighter, not a lot of people are going to beat him,” said 33-year-old Ward, who has 16 knockouts from his 32 bouts.
“But when you are facing a great fighter you have to raise your game to the next level.
“I hurt him with a head shot and I just had to get the right shot in to finish him.”
