The rules have always been a little looser in Mexican professional wrestling but this was a brick too far.

Puerto Rican star Cuervo (The Raven) was knocked unconscious and reportedly had his skull fractured after being blindsided by a brutal blow to the back of his head in a match against Angel o Demonio (Angel or Demon) at the Lucha Libre Boom show.

Cuero was standing on the ground outside the ring when his opponent launched the missile and sent him crashing face-first to the floor.

The “death match” was immediately called off. Angel o Demonio jumped out of the ring to check on his fallen rival but was ordered away by a doctor.

Cuervo was rushed to hospital where surgeons operated to remove a blood clot. “It was an epidural hematoma and he had a skull fracture,” a promoter of the show announced. “He had surgery to drain the clot. He is out of danger, is in intensive care and is responding satisfactorily.”

Warning: Graphic vision

This is totally unacceptable pic.twitter.com/uUPIcu8I7v — Fightful Wrestling (@FightfulWrestle) November 20, 2018

Cuervo’s manager Victor Arroyo announced via his Facebook page the wrestler was recovering well

“We are informed that the operation to the Raven was a success. The clot was removed and is stable,” he wrote. “Thank you all for the prayers and good vibe.”

There are reports a benefit show will be held in Mexico this week to help cover Cuervo’s medical costs.

Angel o Demonio said he was aiming for Cuervo’s back but “did not have the accuracy”.

“I apologise to the entire public because first of all I am a professional,” he said.

But he’s been suspended indefinitely by the Boxing and Wrestling Commission of the State of Mexico and widely condemned. WWE legend Kurt Angle wrote: “Give me 10 seconds with that stupid MFer that threw the brick. Shouldn’t be anywhere near the business.”