On that first Sunday of June 1977, the yellow team secured its leap to the elite after a season in which it demonstrated its superiority in the second division. The decisive match, played at the then-named Ramón Carranza stadium, ended in a 2-0 victory against Tarrasa, sparking a collective euphoria that spread from the stands to the city streets.

The team, managed by Enrique Mateos, achieved the goal on the final matchday, securing its spot as league runner-up with 46 points. That victory was not only an immediate sporting success but also marked a turning point in the club's history, opening a period of greater competitiveness in Spanish football.

The lineup that starred in that historic match included Santamaría, Cenitagoya, Rosado, Barrachina, Ortega, Ibáñez, Carvallo, Villalba, Quino, Mané, and Urruchurtu, with additional appearances by Puig and Ramón Blanco. Goals from Villalba and Ortega in the first half were enough to confirm the promotion.

This event was the prelude to a history marked by resilience. Although the team experienced ups and downs after its debut, the path started in 1977 allowed for the consolidation of a structure that, years later, would reach its best historical period with nine consecutive seasons in the top flight starting from the 1984-85 campaign.