A US martial artist knocked his opponent out cold with an impressive spinning back kick at a tournament in Long Beach, California.

Just thirty seconds after the start of the fight, Duke Creech Jr. attacked his opponent with a beautiful kick which ended the bout instantly.

The opponent was knocked out cold for a few seconds and needed help to stand.

"The opponent received immediate medical care," the filmer wrote online.

"(The figher) has been a martial artist all his life and is a black belt in Kajukenbo. He has competed in many karate tournaments over the years and has ventured into MMA, competing in two amateur MMA matches as well," the filmer explained.

"This is what clean technique looks like! It's not always about power but how well you can execute your technique during a fight," he said.

Although the video was filmed in 2012, it has only recently emerged online.

Duke Creech Jr. has been a martial artist all his life and is a black belt in Kajukenbo. He has competed in many karate tournaments over the years and has ventured into MMA, competing in two amateur MMA matches as well.

This video is from the Long Beach Internationals tournament in 2012.

This is what clean technique looks like! It's not always about power but how well you can execute your technique during a fight.

P.S There was medical staff at this event. The opponent received immediate medical care.