Adam Kownacki said he knew by the first round.

He knew by the opening minutes of the fight, when he was able to land his right hands against his Polish compatriot Artur Szpilka, that he was going to get him sooner or later. After being trash-talked by his better-known opponent leading up to the fight last Saturday, Kownacki wanted to make him eat his words.

“He told me some stuff, like that I’m not on his level. He underestimated me and didn’t give me no chance. That really got me frustrated because I know what I’m capable of,” said Kownacki (16-0, 13 knockouts).

Kownacki made his statement in the fourth round, dropping Szpilka (20-3, 15 KOs) with a barrage of right hands and landing a few more in the corner to convince referee Arthur Mercante Jr. to wave off the fight.

“Everything was landing so good, especially the right hands. It was easy.”

It was an epic night for Kownacki, who brought a loud brigade of fans at the Nassau Coliseum in Long Island, New York to cheer and chant his name throughout. Szpilka, who unsuccessfully challenged Deontay Wilder for the WBC heavyweight title in his most recent fight over a year ago, may be the better known name back home but the majority of fans were cheering for the fighter who now hails from Greenpoint, Brooklyn.

“He’s got these ‘Red Army’ guys wearing the red shirts, ‘Kownacki Power’ guys. If you look at the arena, it was overwhelming from his fans in Jersey and New York area,” says Przemek Garczarczyk, the leading reporter on Polish boxing. He estimates the crowd’s support was split 85-15 in Kownacki’s favor.

The fight was reminiscent in some ways of when Polish fan favorite Tomasz Adamek defeated Andrew Golota in 2009, and then the torch was passed when Szpilka outpointed Adamek in 2014. The primary difference is that both Golota and Adamek were well past their best years when they lost, and both Szpilka and Kownacki are in their physical primes at 28.

“I think Szpilka was the best heavyweight boxer in Poland, most known at least other than Adamek,” said Kownacki. “I’m the top dog now.”

Kownacki was born and raised in Łomża, Poland before coming to America at age 7. The fight boosted his profile in his native country, with one video of the fight being viewed on YouTube over one million times in three days.

It was his first time to have one of his bouts shown live in Poland, where it was televised on Polsat. Garczarczyk says the four weeks Kownacki spent in Poland as Adamek’s chief sparring partner for his comeback fight against Solomon Haumono was Kownacki’s first significant exposure in the country.

“This was the first time when people could see Adam every day because (Adamek’s fight) was a big deal in Poland,” said Garczarczyk.

“I went to the Polish soccer game and people recognized me at the stadium; they recognized me at the airports. It wasn’t crazy but I was pretty well-known,” said Kownacki of his time in Poland.

“Now after this win, it exploded. My Facebook exploded; my internet exploded.

“I think my life is gonna change and I just gotta be focused, be humble and keep doing what I’m doing.”

Kownacki, who is handled by Al Haymon’s Premier Boxing Champions, is content to enjoy his victory and allow the matchmakers decide what comes next. He describes the eight weeks he spent in training for this fight as “lonely” away from his wife, whom he had met while rehabilitating an arm injury, which kept him out of the ring from 2010 to 2013.

Even with the win, those closest to his career are keeping everything in perspective for him.

“There’s still a lot of work to be done. As soon as we finished the fight, (head trainer) Keith Trimble gave me a list of things we were doing wrong, instead of congrats,” said Kownacki, who trimmed down to 242 pounds from nearly 258 pounds for his previous fight in January.

All things considered, he’s not in a bad position.

“It took Wilder (nine) rounds to get rid of (Szpilka). It took me four. I think that makes a statement right there,” said Kownacki.