On June 29, 2007, CMLL's annual "Gran Alternativa" tournament took place at Arena Mexico. Guerrero teamed up with Euforia, but the team was defeated by Místico and his partner La Sombra. After the loss Guerrero publicly asked Dr. Wagner, Jr. to join him for a challenge to Místico and Negro Casas for the CMLL Tag Team Championship. The match was held on July 13, 2007 at Arena Mexico and saw Guerrero and Wagner win the championship. A week later Guerrero and Wagner lost the titles back to Místico and Casas, making the team the shortest reigning CMLL World Tag Team Champions ever. The loss caused the two fighting in mutual accusations of betrayal, which in turn led to a feud between the two wrestlers. On July 27, at Arena Mexico, Dr. Wagner, Jr. and Místico held a "mano a mano" match which was decided by a treacherous intervention by Guerrero, who climbed into the ring, attacked Wagner from behind and caused him to lose the match, then the aftermath, Guerrero ripped off Wagner's mask. On August 3, 2007, Guerrero teamed up with Atlantis and Sangre Azteca against Dr. Wagner Jr., Alex Koslov and Volador Jr. at Arena México after the match Guerrero took the microphone and challenged Wagner for a mask versus mask match but no match ever came of it as Dr. Wagner, Jr. left CMLL shortly after. In 2008 Último Guerrero teamed with newcomer Dragón Rojo Jr. to win the 2008 "Gran Alternativa" tournament.