Mexican wrestler Pedro Aguayo Ramirez has died from a blow suffered in the ring.
The 35-year-old, known as Hijo del Perro Aguayo, fell unconscious on the ropes, apparently after receiving a flying kick from fellow wrestler Oscar Gutierrez, known as Rey Mysterio Jr, according to video of the match in a municipal auditorium in Tijuana.
The match continued for almost two minutes before other participants and the referee realised Aguayo was seriously injured and tended to him.
He was taken to a nearby hospital and died about 1.30am local time yesterday, said Raul Gutierrez of the Baja California state prosecutor's office.
"I have no words for this terrible news," Joaquin Roldan, director of the AAA wrestling federation, said on Twitter. "My sincerest condolences for the Aguayo Ramirez family."
The state prosecutor's office said the cause of death, based on a post-mortem examination, was trauma to the neck and a cervical fracture. It has opened an investigation into possible manslaughter.
The company that reportedly organised the event, The Crash, could not be reached for comment.
The Tijuana Boxing and Wrestling Commission called the death an unfortunate accident like those that occur in other high-risk sports.
Even though the match continued as Aguayo hung listless on the ropes, commission president Juan Carlos Pelayo said people moved immediately to check his condition.
He said the doctor in charge was not at ringside because he was treating another injured wrestler, but paramedics and a doctor who was a spectator attended to Aguayo.
"The reaction for medical attention was quick, in my opinion," Mr Pelayo said.
Mexico is famous for its colourful characters and costumes in professional wrestling, popularly known as lucha libre, where fighters perform daring aerial manoeuvres inside and outside the ring.
Aguayo had wrestled for 20 years and was the son of the renowned Pedro "Perro" Aguayo, now retired and a member of the Aztec lucha hall of fame.
The younger Aguayo was also popular and led a group called "Los Perros de Mal," or the bad dogs.
He won numerous titles, including national pairs with his father, a national heavyweight championship and the Consejo Mundial Lucha Libre world trios championship.
"It makes me very sad because he was a professional colleague and I have great affection for his father," the wrestler Hijo del Santo said.
"I think the fans in Japan, the US and Mexico, of course, where he was very popular, must be in mourning, especially because of his youth. He had much ahead of him."