Fahd Abbou El Mourabit was punched in the back of the head by a player while officiating a match in Zaragoza's regional first division between teams Miralbueno and San Juan.
The incident occurred 28 minutes into the clash when El Mourabit awarded a second penalty against home side Miralbueno.
The ruling infuriated Miralbueno's number 14 who struck the referee with full force, knocking the match official out. The onslaught of punches didn't end there with the player continuing to hit El Mourabit on the ground until he was restrained by team mates.
El Mourabit was taken to hospital after the ferocious attack with bruising to his neck, head and face. The game was suspended following the incident.
"I did not expect anything," El Mourabit told Spanish radio station Cadena SER.
"Even after I hit the ground, the punches kept coming until team mates intervened.
"Clearly I'm going to report this incident but I want to make clear that this will not kill my passion for refereeing and football."
Miralbueno's club vice president said it was a regrettable incident.
"All we can do is apologise to the referee because this should not happen on any football pitch.
"This action has to be met with the hardest of punishments."
Miralbueno confirmed the player responsible has been released from the club.