The professional wrestling world has lost a true legend.
Miguel Ángel López Díaz, better known by his ring name Rey Misterio Sr., has passed away at 66 years old, per an announcement from his family.
Lucha Libre AAA Worldwide has also released a statement following the news.
"We regret the sensitive death of Miguel Ángel López Días, known as Rey Mysterio Sr.," the promotion said in a statement (translated from Spanish). "We send our most sincere condolences to his loved ones and raise our prayers to heaven for his eternal rest."
Misterio Sr. is most well-known nowadays for having trained his nephew Rey Mysterio, one of the most popular professional wrestlers of all time.
Additionally, Misterio Sr. trained other professional wrestling legends like Konnan, Psicosis, Halloween, and Damian 666. He also trained his son, Rey Misterio Heredero, who is better known as El Hijo de Rey Misterio.
Misterio began his professional wrestling career after training to be a boxer. He made his in-ring debut on Jan. 6, 1976, on at Día de los Reyes, translated to "Day of the Kings."
Misterio would go on to become wildly popular in Mexico and wrestled in multiple promotions, including Lucha Libre AAA Worldwide, Pro Wrestling Revolution, Tijuana Wrestling, and World Wrestling Association (WWA).
Misterio also appeared in World Championship Wrestling (WCW) in 1990 as part of the "Pat O'Connor Memorial International Cup" during the Starrcade pay-per-view. He represented Mexico alongside Konnan.
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Misterio has won multiple titles, including the IWC World Middleweight Championship twice, the America's Championship, the Tijuana Welterweight Championship, and the WWA World Junior Light Heavyweight Championship.
In addition to his singles titles, Misterio won the WWA Tag Team Championship with his nephew and the Revolution Tag Team Championship with his son.
Misterio was inducted into the Tijuana Sports Hall of Fame in 2006 and retired from professional wrestling in 2009. Despite that, he wrestled his final match in 2023.
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Multiple tributes have poured out for the wrestling legend.
"So sorry to hear about the death of the original Rey Misterio (Sr.), Miguel Lopez, at 66, the uncle of the WWE star," said Dave Meltzer of Wrestling Observer. "In his heyday he was almost like Tijuana's version of Jerry Lawler in Memphis."
@elClubLucha re-shared a compilation video they made of Rey Misterio Sr. and Rey Mysterio Jr. teaming up, simply saying, "RIP Rey Misterio Sr."
Everyone here at Newsweek Sports sends their condolences to Misterio's family and friends.