A prank on UFC fighter Raúl Rosas Jr. went wrong when the young fighter knocked out the content creator who tried to provoke him.

In a video posted on both the prankster’s and Rosas Jr.'s social media, the Mexican fighter is seen being interrupted at the gym by a YouTuber named Aris Sureni, also known as "Opto."

A Risky Prank

Opto began bothering Rosas Jr. by accusing him of using “his” treadmill. In an attempt to avoid conflict, the fighter switched machines.

"I find it disrespectful that you're using my treadmill right now," the YouTuber remarked.

But Opto didn't stop there. He came back and took the weights from Rosas Jr., prompting the fighter’s team to warn the prankster to back off. Ignoring the warning, Opto, from the YouTube channel Topnotch Idiots, kept pushing, leading the 20-year-old UFC fighter—who has a record of 10 wins—to respond with a punch.

The visibly nervous content creator then challenged Rosas Jr. to a fight in the cage. Once inside, Rosas Jr. immediately knocked him to the ground with a solid punch, followed by a hold that left the prankster unconscious.

Between laughs and gasps, Opto admitted that it was all a prank, prompting Rosas Jr.'s team to step in and release him.

Finally, in a more relaxed atmosphere, Rosas Jr. and his companions acknowledged Opto's nerve in attempting such a prank.