Legendary Mexican professional wrestler and trainer Rey Misterio Sr., the uncle of WWE Hall of Famer Rey Mysterio and great-uncle of WWE superstar Dominik Mysterio, has died at the age of 66.

According to Sam Palmer of Wrestling Inc., Misterio turned pro in 1976 and remained active until 2009. However, he came back for games a few times, his last coming in 2023.

Misterio starred in several Mexican promotions, including the World Wrestling Association. He won the WWA World Junior Light Heavyweight Championship once and also won the WWA Tag Team Championship with Rey Mysterio Jr.

Misterio also appeared at WCW Starrcade in 1990 and took part in a tournament. He and Konnan defeated Norman Smiley and Chris Adams in the quarterfinals before losing to Scott and Rick Steiner in the semifinals.

According to Thomas Lawson of SE Scoops, Misterio opened a gym in 1987 alongside professional wrestlers Negro Casas and Super Astro. He also trained talents such as Konnan, Psicosis and Mysterio.

According to al.com’s Ben Flanagan, Misterio was inducted into the Tijuana Sports Hall of Fame in 2006.

Dominik Mysterio and his sister Aalyah Mysterio shared their reactions to the news of the tragic death.

Many also expressed their condolences and fond memories on social media.

Our condolences, thoughts and prayers go out to the family at this difficult time. The Mysterios are also still mourning the passing of Roberto Gutierrez, Rey Mysterio Jr.’s father and Dominik’s grandfather November 17th at the age of 76.