Never judge a book by its cover; you might end up picking a fight with the wrong person.

A physical altercation at a Penang convenience store went viral, impressing many with the store owner's strength and quick reflexes as he landed multiple punches. It turns out the owner holds a black belt in taekwondo and won the Penang International Taekwondo Federation (ITF) championship in 1996.

He has also shared his self-defense knowledge with others.

"In 1998, a Taekwondo coach was busy and couldn't teach, so knowing my skills, he asked me to step in and teach his students," the owner recalled. That year, he coached four times and was even offered a full-time position, but he declined to focus on the family business.

In an interview with China Press, the owner revealed that the customer who fought him was not a regular, having only visited the shop twice.

"In a rude manner, the customer demanded a can of beer and even challenged me to a duel," he said.

The owner filed a police report, and as of yesterday, both men have been arrested. He also clarified that the incident was not racially motivated or related to alcoholism but was purely a personality clash.