Andre Ward retained his WBO, WBA and IBF light-heavyweight belts after stopping Sergey Kovalev in the eighth round of their rematch in Las Vegas on Saturday night.

Ward overcame Kovalev on points to win all three titles last November, and the American beat the Russian once again to ensure that he is now unbeaten in 32 professional fights.

Kovalev, who revealed after the bout that he wants another rematch, struggled to cope with Ward's power in the second half of the contest, and a flurry of body shots saw the referee call time in the eighth round.

Both fighters had their moments in the early exchanges, with Ward testing Kovalev with a crisp right hand in the opening round, but the Russian enjoyed success in the second when he was allowed to get close to his opponent.

Ward has now produced 16 knockouts from his 32 professional bouts.