Kadiru (23-2, 13 KOs) accepted the fight on approximately five days’ notice after Tony Yoka withdrew because of injury. The German entered the bout as the WBA Continental heavyweight champion and was fighting for a world title for the first time.

Despite giving away several inches in height and roughly 25 pounds, Gassiev quickly took control by cutting off the ring and forcing exchanges at close range. He repeatedly landed hooks to the head and body while backing Kadiru toward the ropes, limiting the challenger’s ability to use his reach advantage.

Kadiru remained on his feet through five rounds but struggled to generate sustained offense as Gassiev continued applying pressure. The end came in the sixth when the champion trapped Kadiru along the ropes and landed a series of clean combinations. Seeing their fighter badly hurt, Kadiru’s corner threw a white towel into the ring, prompting the referee to stop the contest.

The bout was originally scheduled to be Gassiev’s first title defense against Yoka before the Frenchman withdrew during fight week. Kadiru accepted the opportunity on short notice, replacing Yoka less than a week before the event.

Gassiev has now won consecutive heavyweight bouts over Pulev and Kadiru since capturing the WBA Regular title. Saturday’s victory improved his heavyweight record to 10-2 and kept him in possession of one of boxing’s four recognized heavyweight world championships as he awaits confirmation of his next opponent.