Dorados de Sinaloa, or Dorados, is a Mexican professional football club based on Culiacán, Sinaloa, Mexico. History Dorados de Sinaloa was founded on August 9, 2003. The Dorados was the youngest team to play on First Division de México, having joined the division for the first time for the Apertura 2004 tournament when the club was only one year old. The Dorados currently play in the Liga de Expansión MX, the second tier of the Mexican league. First promotion and relegation On 20 December 2003, the Dorados won their first title in the Apertura 2003 tournament of Primera División A. Guadalupe Castaneda scored the goal, beating the Cobras of Ciudad Juárez. They finished as runners-up in the Apertura 2004, and won the play-off promotion beating Club León with a goal from Roberto Dominguez and winning the promotion to Liga MX just one year after the club was founded. The club was relegated to the Apertura in a 2006 tournament after playing for just two years in the top tier. Return to first Division On July 27, 2015, the Dorados played their first game in the First Division after 8 seasons in the Second Division. The game was celebrated in the Banorte Stadium versus Jaguares de Chiapas, with a 0–0 final score. Their first 3 points came in the second game of the season on July 31, against Xoloitzcuintles de Tijuana in the Caliente Stadium. Dayro Moreno scored for the North Californian team, but Mauricio Martín Romero scored the first goal of Dorados in the 2015–16 Liga MX season. The Dorados played and won their first game in the first division in 9 years, 1–2. The previous game being on April 22, 2006, when the Dorados beat Jaguares de Chiapas 4–2, with goals from Andrés Orozco, Cristian Patiño, and Pepe Guardiola. Second relegation On April 16, 2016, after losing 5–2 to Tigres UANL, the Dorados were demoted after just one season in Liga MX, finishing last in the relegation table of 2015–16 Liga MX season marking the second time the club was relegated to Ascenso MX. Rivalry with Club León When the Dorados de Sinaloa arrived at Primera División A in 2003, a rivalry was born. When the franchise was first created in 2003, Dorados became champions in their first tournament, becoming the first team to ever accomplish this feat in Primera A. In their second tournament, Dorados made it to