By Keith Idec

NEW YORK – Adam Kownacki was in a tougher fight this time, but it didn’t stop the popular Polish heavyweight from producing his second straight noteworthy knockout.

Bleeding badly from his nose for much of the fight, Kownacki knocked out Iago Kiladze in the sixth round of a scheduled 10-rounder on the Errol Spence Jr.-Lamont Peterson undercard at Barclays Center. Kownacki floored Kiladze once apiece in the fourth and sixth rounds before referee Shada Murdaugh halted the action at 2:08 of the sixth.

Kownacki’s crushing right uppercut snapped back Kiladze’s head late in the sixth. He followed it up with an overhand right that sent Kiladze stumbling backward and to the canvas.

Kiladze got up, but his trainer, Freddie Roach, instructed a New York State Athletic Commission inspector to tell Murdaugh to stop the fight.

The Polish-born, Brooklyn-based Kownacki upped his record to 17-0 and produced his 14th knockout.

Kownacki scored the most impressive win of his eight-year pro career in his previous bout. The 28-year-old Kownacki stopped Polish rival Artur Szpilka in the fourth round July 15 in Uniondale, New York, but weighed in 18 pounds heavier for this fight (260) than he did when he fought Szpilka (20-3, 15 KOs).

Prior to Saturday night, Georgia’s Kiladze (26-2, 18 KOs) lone loss came in a cruiserweight bout. Youri Kalenga knocked out Kiladze, 31, in the second round of that June 2013 fight in Berlin.

Prior to the sixth-round knockdown that signaled the end of the fight, Kiladze hit the canvas approximately 30 seconds into the fourth round. He claimed he was pushed once he got to his feet, but Murdaugh counted it as a knockdown caused by Kownacki’s right hand.

Kownacki kept coming forward during the third round, yet by then both boxers already appeared tired.

Following an action-packed first round, the pace slowed somewhat in the second round. Kownacki continued to press the action, but landed few effective power shots until unloading multiple right hands that landed in the final 20 seconds of the second round.

Kownacki attacked Kiladze right after the opening bell. They began trading power shots about a minute into the first round, when Kownacki came away from those exchanges with a bloody nose.

Kownacki and Kiladze each landed hard right hands later in the first round. A ringside physician checked Kownacki’s nose before allowing the second round to begin.

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