After five straight losses, the end may be here for Adam Kownacki.

The former heavyweight contender returned home to his native Poland on Saturday for what he hoped would be a career rebirth, but he instead suffered a 45 second technical knockout loss to local prospect Kacper Meyna in the town of Koszalin

Kownacki (20-5, 15 knockouts) was caught in the corner early on and had no answer for the opening barrage from Meyna (12-1, 8 KOs), who stunned Kownacki with a right hand and a hook and never stopped throwing back. Had the fight been an amateur bout, Kownacki would have gotten a standing eight count, but without any place to escape, nor defense to slow his attack, referee Leszek Jankowiak had no choice but to stop the fight.

The win is the seventh straight for the 24-year-old Meyna, whose only defeat came in May of 2021, when he lost a close but unanimous decision to Mateusz Cielepala.

For Kownacki, 34, of the Greenpoint section of Brooklyn by way of Lomza, Poland, a series of hard fights throughout his pro and amateur career appear to have caught up with him. Though he had become the most popular local draw during the heyday of Brooklyn boxing at the Barclays Center, a series of crushing stoppage losses to Robert Helenius, followed by less defensible losses to Ali Eren Demirezen and Joe Cusumano, signaled that his losses weren’t a matter of having one off night.

The Meyna-Kownacki upset wasn’t the only shocking heavyweight action to take place on the card.

Earlier in the night, Marcin Sianos, a pro MMA fighter with 15 bouts to his credit, made his boxing debut against undefeated fighter Artur Bizewski (9-0, 4 KOs) in a bout scheduled for six rounds. Sianos hurt Bizewski badly with a series of right hands, but then forgot which sport he was competing in as he took Bizewski down to the mat and elbowed him in the mouth, causing an immediate disqualification.