YouTube boxer Logan Paul watched in amazement as Maksymilian Lesniak flattened rival Nikolas Toth in their contest at the Slap Fighting Championship.
Lesniak - known as Mad Maz - landed a perfect blow with his right hand which sent Toth - The Predator - flying backwards.
And in a clip posted to his social media, Paul is shown open-mouthed as he reacts in astonishment to events in front of him.
Paul was hosting the event with Arnold Schwarzenegger and both were present to watch the action unfold.
And Lesniak didn't disappoint, landing the 'fight' winning blow with his first slap of the contest.
Toth fell backwards into the arms of two minders and the contest was unsurprisingly waved off. The beaten man was tended to by medics but appeared to have recovered.
Paul said earlier this week that he was honoured to be hosting the event alongside Schwarzenegger.
"It makes me so happy to be here right now. My dad took me to the Arnold 10 years ago. It’s so cool to be back here hosting Slap Fighting Championship," he said.
"I was with the fighters yesterday. These guys are the toughest, burliest most brawny people you’ve ever seen in your life.
Would you try slap fighting? Let us know in the comments section below
"This event is absolutely insane. Who knows what’s going to happen? Tomorrow, people are getting knocked out via slaps to the face.
"We have five big fights, featuring Koa for the super heavyweight championship against a 6’ 1” 310-lb polish dude named ‘Zales’ who is undefeated. Trust me, you don’t want to miss it. This is going to be crazy. Absolutely absurd.
"I’m a grassroots slap fighting fan. I was one of the first to see it going viral on YouTube. These men are behemoths. They already have marks on their faces and welts. It’s like they’ve been practicing being hit."
