(NewsNation) — Mixed martial artist Ro Malabanan wasn’t on the mat or in the cage, but he knew exactly what to do when he says he saw a man assaulting others in New York City’s Soho shopping district.

Malabanan had just gotten off the train to go to his boxing instructor job, according to the New York Post, and was walking toward the gym when he noticed two men walking toward him, laughing and joking.

Then, “out of nowhere,” a third man walked behind one of them, sucker-punching him on the side of his face.

The man who was punched stumbled, so his assailant was able to get away.

When Malabanan went to check on him, two other men walked up to him and he asked if they had been hit, too.

“Apparently, he hit an older man and a younger person a few blocks away,” Malabanan told NewsNation’s “Morning in America.” “So I immediately went into my martial arts mode.”

Malabanan ran after the alleged attacker, who was a block away.

“I was like, OK, yeah, we have to put a stop on this guy, because I’m thinking about my parents who are older and how they would feel if they got hit,” he said.

Malabanan assessed the situation at first.

“I thought that if I confront him … it’s going to be a full-on brawl,” he explained. “Worse, he may have a knife or a gun.”

Then, however, Malabanan’s “jiu-jitsu instincts” kicked in.

“I just grabbed him, I was able to get what’s called a seatbelt position from the back,” Malabanan said.

When the suspected assailant tried to fling Malabanan off him, the martial artist used that momentum to drag him to the ground, subduing him in less than 30 seconds.

Police identified the assault suspect as Samuel Frazier, the New York Post reported. An initial police investigation revealed that Frazier allegedly attacked a 50-year-old man and a 17-year-old boy, the newspaper said.

After practicing jiu-jitsu for 10 to 12 years, Malabanan said what happened was like “a normal day” for him. He’s even faced other potentially dangerous situations before.

“I’ve actually had to chase after another kid one time where he stole a cellphone from another person. And it just things happen so fast in New York is just like you just got to act,” he said. “I don’t do this as a habit. But when presented, I feel like I have a responsibility as a martial artist and also as a New Yorker.”