Suzuki and René Duprée on the December 9 episode of SmackDown!. They successfully defended the title against the former champions at Armageddon on December 12, before losing the title to the Basham Brothers on the January 13, 2005, episode of SmackDown! after Van Dam was injured. Mysterio then teamed up with Eddie Guerrero to win the WWE Tag Team Championship back from the Bashams at No Way Out on February 20. In a departure from traditional booking, the new champions did not defend their title at WrestleMania 21 on April 3, but instead had a match against each other which Mysterio won. He once again defeated Guerrero at Judgment Day on May 22 by disqualification. At ECW One Night Stand on June 12, Mysterio faced and defeated long-time rival Psicosis for the first time in nearly five years. The match at WrestleMania was part of a storyline in which Guerrero turned on Mysterio and beat him up after abandoning him during a match against MNM for the WWE Tag Team Championship. After a no disqualification match against Chavo, Eddie came out and slammed Mysterio on the steel steps, displaying Eddie's increasing frustration with being unable to defeat Mysterio. Guerrero and Mysterio continued to feud, with Guerrero threatening to reveal a secret he and Mysterio shared involving Mysterio's real life son Dominik, unless Mysterio deferred to Guerrero's authority. Guerrero later revealed that, in the storyline, he was Dominik's biological father. The storyline went that Guerrero knew Mysterio was having trouble starting his own family, so Guerrero left Dominik as a baby with Mysterio and his wife Angie to raise. Guerrero threatened to take custody of Dominik, drawing up custody papers and having his lawyer present them to Mysterio. At SummerSlam on August 21, Mysterio defeated Guerrero in a ladder match for the custody of Dominik. On November 13, 2005, Eddie Guerrero was found dead in his hotel room in Minneapolis, Minnesota. That same day at a WWE "Super Show" where SmackDown! and Raw were both taped, Mysterio gave an emotional speech about Guerrero, and in a show of respect removed his mask (though he put his head down, so his face could not be seen). Mysterio went on to defeat Shawn Michaels in an interbrand match later that night. After the match, Michaels and Mysterio hugged in the ring and Mysterio pointed up to the sky, crying, in memory of Guerrero.