Adrian Kaczmarek was caught on a cellphone video taking down a shirtless disorderly passenger on a subway train in the Los Angeles area on March 19 (video below).
The 25-year-old shirtless man got into a verbal altercation with several passengers, prompting one to hold up his bicycle as protection.
As the shirtless man harassed another passenger, Kaczmarek grabbed him from behind in a headlock and slowly took him down to the floor where the man passed out.
"Damn, this is going viral," the unidentified man filming the incident can be heard saying.
"You knew that there was going to be some sort of physical altercation so I wanted to put a stop to that before anything else happened," Kaczmarek told KABC.
The Los Angeles County Sheriff’s Department said that the train was traveling from Crenshaw to Culver City.
"I was more concerned about my safety and the people on the train's safety," Kaczmarek told KNBC. "I wasn't sure if he had a knife or if he had a gun."
"And when I finally saw it escalating to the point where he was obviously getting physical and people were getting pushed around," Kaczmarek added, "the whole thing is about to explode. I thought the best thing to do was just to go over there and subdue him."
Kaczmarek kept the man on the floor with his foot while the train conductor called transit deputies.
The shirtless man struggled when a female transit deputy arrived, but Kaczmarek was able to use the deputy's handcuffs -- with her permission -- to restrain him at the Culver City Station.
The clothing-optional man was reportedly charged with suspicion of being under the influence of a controlled substance.
KNBC notes that Kaczmarek is a fitness trainer.
After the video went viral on the Web, Kaczmarek was dubbed "Viking Guy" because of his beard, muscles and Viking-like strength, reports Daily Mail.