Kickboxing: Fighter knocked out after turning back, sparking wild brawl

A kickboxer has painfully learned never to turn your back on an opponent when he was brutally cold-cocked from behind after inexplicably giving up during a round. 

However, there was a price to pay for the destructive knockout with fans storming the ring and attacking the victor. 

Armenian Harut Grigorian was fighting Dutch opponent Murthel Groenhart when all hell broke loose in the second round of Glory 42 Kickboxing Championship in Paris. 

The drama began when Groenhart connected with a bruising flying knee around the third minute mark. 

The blow to the head seemed to have dazed Grigorian who suddenly quit on the round. 

However, Groenhart hadn't given up on the fight. 

The Dutchman raced up behind Grigorian and landed a perfectly legal hit as his opponent tried to walk back to his corner. 

The knockout blow immediately dropped an unconscious Grigorian. 

However, the sweet taste of victory was quickly soured for Groenhart when fans invaded the ring an assaulted him as he celebrated. 

Around three fans attacked Groenhart before security could stop the wild melee and protect the fighter. 

Groenhart was eventually crowned the winner but it was reported after the fight his jaw had been broken in the attack.