In the finals, Tigres lost 1–3 and 1–0 (3–2) once more against Pachuca in the Estadio Universitario. In the Clausura 2004, Argentine striker Andrés Silvera finished the tournament as one of the top goal scorers, but Tigres ended in 12th place and missed the play-offs. That same tournament they scored the biggest result in a Clásico Regiomontano, beating archrival Monterrey 6–2. In October 2004, Sinergia Deportiva purchased the rights to a franchise in the MISL called the "Monterrey Tigres". However, due to conflicts with the previous MISL franchise "Monterrey Fury", the team elected not to complete the purchase of the team, and the MISL terminated the indoor franchise in December 2004. In the Clausura 2005, Tigres went to postseason and tied with Monarcas Morelia 2–2 and 2–2 (4–4) in the quarter-finals, and Morelia went to the next stage because of the points they achieved in the regular season. In the Apertura 2005, Walter Gaitán finished the season as the top scorer of the tournament and Tigres went to play-offs in 8th place. In the quarter-finals, under the command of the iconic Osvaldo Batocletti, Tigres played the historical "Aztecazo", a way to describe a difficult victory over América or the Mexico national team in their venue, the Estadio Azteca. In the first game, Tigres lost in the Estadio Universitario by a 1–3 score. Against all odds, however, they defeated América in the second game 4–1 for an aggregate scorline of 5–4, leaving América out of the postseason. In the semi-finals, Tigres drew Monterrey after 1–0 and 1–2 (2–2) scorelines, although Monterrey progressed to the next round because of the points in the tournament. On 3 August 2006, CEMEX, the company that controls Tigres, celebrated its first 100 years with a match between Tigres and Barcelona in Monterrey. The game ended with the locals losing by 3–0. Sindey Balderas of Tigres scored an own goal, Ronaldinho scored with a free kick and later passed to Eiður Guðjohnsen for a third goal. Tigres finished the Clausura 2007 season as eighth with 23 points, securing play-offs.