At that point, with the fight in its opening three seconds, the two fighters were still only visible via a rotating bird’s-eye-view camera shot.

Many expected Jurk, the undefeated and hard-hitting German southpaw, to win inside the distance against the 13-2 Edwin Castillo, but, evidently, nobody expected it to end so soon.

“When I heard the bell ring I thought ‘ok, I’m moving forward,’” Jurk tells The Ring. “I’ve seen he has opened himself up wide so I thought ‘OK, let’s give this a try.’”

After half showing Castillo a jab, the 26-year-old unleashed an arcing left hook from his southpaw stance which started somewhere around his waist and eventually seemed to nestle inside his opponent’s left shoulder.

Whatever it hit, Castillo went straight over, laid out flat on his back for some time. Given how rare a single-punch fight is, the clip went viral instantly, although much of the response centered around Castillo’s peculiar reaction rather than Jurk’s win.

But for the victor, who improved to 14-0 with 12 quick, it was a case of job done, especially as this first-round knockout had caused more of a stir than his previous nine put together.

“In Germany they know me for my quick KOs,” he adds. “That was No. 10 in the first round so people know that about me.

“I always try and get this first round KO because my dad used to tell me that you will get popular quickly with that. If you fight for rounds and rounds, nobody cares.”

The result, which took place on May 15 in Mannheim, means he has now been involved in just 30 rounds of boxing in the 14 fights since his debut in 2021. Of those 30, he has completed just 18. And while compiling such a record is solid currency for any emerging heavyweight, there comes a time when he will need to be stepped up.

“Of course I’m ready for that step up now,” Jurk counters quickly. “I’m always training. 

“People always ask me why I win so fast, they ask why I don’t get some rounds but I tell them, listen, I train so much. Maybe if I didn’t, the fights would go on for longer.”

Winning has not always come so easily to the heavyweight from Flensburg in northern Germany. In terms of boxing, it is a place synonymous with Wladimir Klitschko, who boxed for BC Sparta Flensburg in the Bundesliga from the age of 19.

It was Jurk’s dad who had steered his 10-year-old son towards the sport in order to give him some basic grounding in self-defense. But things did not start well as he lost his first three bouts and was 3-7 after 10.

“When I start something and I love it, I want to reach the limits,” he says. “I was losing but I knew it was part of learning. As I got older and more confident I started winning. After I won my first national title in the amateurs as a junior my dad said I can retire from the sport because he knew I could protect myself by then.

“But by that point I thought that if I won the nationals, why is it not possible to reach the world level?”

Now 16 years on, Jurk is attempting to gatecrash an incredibly competitive heavyweight scene. He has seen the No. 1 heavyweight up close having sparred Oleksandr Usyk ahead of both of his fights against Tyson Fury in 2024.

But the 26-year-old knows as well as everyone that 13-second knockouts against the likes of Castillo will not necessarily help his climb towards the top, as handy as they are for building his profile.

That victory was his third of the year already after managing just one fight, a first-round knockout, in a frustratingly slow 2025. He currently juggles his professional career with a degree in business administration and, after such a busy first half of the year, Jurk is now not expecting to box until the autumn. Then, he is hoping to secure a fight with one particular British heavyweight.

“I’ll be back maybe September, October and then November and December,” he says. “It all depends on the plan for next year and if we are going for a title next year.

“Johnny Fisher is a target. But he has potentially 10 people calling him out because we all know that he sells tickets. He’s a proper British heavyweight and he can make you famous.

“I would fight anyone out there. I would love to fight Fisher but I know he won’t take the fight. I just call him out anyway, it makes no difference does it? It’s all just noise.”

But noise, as he found out in Mannheim, can take you a long way in this sport.