When a thief stole a restaurant customer's phone on Thursday, he really didn't expect the restaurant's co-owner, who happens to be a martial arts expert, to track him down and knock him out.
Jason Chan told the Chicago Sun-Times that he was suspicious of the "disheveled" man as soon as he entered the restaurant. He kept an eye on him and witnessed him asking the bartender for a piece of paper and a pen before placing his jacket on the bar. The man then quickly grabbed his jacket and ran out of the restaurant.
Suspecting something was amiss, Chan asked the customer closest to the suspicious man, a regular, if he still had his phone that was sitting on the bar. The customer told Chan that his iPhone 5 was missing, confirming his suspicions.
As the customer went to file a police report, Chan left the restaurant to hunt down the thief.
"I have a protective nature, I guess," he told the Sun-Times.
After some searching, Chan reportedly saw the man -- wearing a distinctively striped sweater -- walk into Lou Malnati's Pizzeria in Chicago.
He confronted the thief and the two "engaged with each other" as the criminal tried to push Chan out of the way to flee. So Chan "grabbed him and threw him into the door."
The thief remained "adversarial" so Chan says he used "hand-to-hand combat techniques to make sure he was unconscious."
"I put him in a maneuver called an arm bar and told him I would break his arm if he tried to get away," Chan said.
When the man refused to quit fighting him, Chan reportedly knocked him out with a hard kick to the face and restrained him until police arrived.
Jason Chan restrains the alleged iPhone thief, Justin Ballog, and calls the police on Nov. 7. Photo courtesy Eric Sawitoski.
Police arrested 37-year-old Justin Ballog, who later admitted that he stole the phone.
Chan said he has practiced and taught Shidokan for 19 years, but he hasn't had to use it outside of the gym in more than a decade. Unfortunately for Ballog, he broke that streak.
More from CBS Chicago: