Tajiri would leave the Cruiserweight division and moved to the tag team division where he formed various tag teams, many of which were somewhat comical. These included Rey Mysterio, Funaki, and Rikishi. Five days prior to the 2003 Judgment Day show, Chavo tore his biceps, forcing Eddie Guerrero to look for another partner. He chose Tajiri. They won the WWE Tag Team Championship, at Judgment Day by defeating Team Angle (Charlie Haas and Shelton Benjamin) in a ladder match. The following week, Guerrero and Tajiri managed to retain their title by cheating. In addition, they also defeated Roddy Piper and his protégé Sean O'Haire at Madison Square Garden. After Guerrero and Tajiri lost the titles to The World's Greatest Tag Team (formerly Team Angle) on the July 3 episode of "SmackDown!", Guerrero turned on Tajiri, slamming him through the windshield of his lowrider truck. On the next "SmackDown!", Guerrero explained that this was because, during the match, Tajiri had accidentally hit his lowrider. At SummerSlam, Tajiri competed in a Fatal four-way match for the WWE United States Championship but failed to win the title.