Salvador Guerrero Llanes was a Mexican-American professional wrestler, a member of the iconic Guerrero family. The son of Gory Guerrero and the older brother of stars like Héctor and Eddie Guerrero, Chavo Sr. had a distinguished career in professional wrestling, particularly in WWE, UWF, AWA, and NWA.

Throughout his career, Guerrero Sr. became a 15-time NWA Americas Heavyweight Champion, participating in major rivalries and high-profile matches, including memorable feuds with Roddy Piper, Gino Hernandez, and The Rock 'n' Roll Express. He also wrestled in All Japan Pro Wrestling and Mid-South Wrestling, where he left a significant mark during the 1980s.

In 2004, he returned to WWE as Chavo Classic, and at 55 years old, he became the oldest WWE Cruiserweight Champion in history. During his time in WWE, he had a prominent feud with his own son, Chavo Guerrero Jr., culminating in several high-profile matches. His tenure in WWE was brief, and he was released that same year.

Throughout his life, Guerrero Sr. was also part of a class-action lawsuit against WWE for brain injuries sustained by wrestlers during their careers, though the lawsuit was dismissed after his death.

Guerrero Sr. passed away at the age of 68 from liver cancer in February 2017. Throughout his career, he left behind a legacy of skill in the ring, and his family remains one of the most influential in professional wrestling.