In early 1997 AAA began a working relationship with the North American-based World Wrestling Federation (WWF), with AAA sending several of their wrestlers to the US to work WWF shows. Estrada made his only WWF appearance when he worked a match at the 1997 Royal Rumble where he teamed up with Fuerza Guerrera and former rival Heavy Metal, losing to Héctor Garza, Perro Aguayo, and El Canek. Estrada was also one of the first participants in AAA's "Rey de Reyes" ("King of Kings") which would become an annual tournament. In the first round, Latin Lover outlasted Estrada, Máscara Sagrada Jr., and The Killer. At Triplemanía V-A Estrada teamed up with El Picudo to be one of four teams competing in a "Luchas de Apuestas" match. Estrada and his teammate survived the match without losing their hair, which ended with Leon Negro pinning Halcón Dorado Jr.