6 Apr 1903 – 8 Apr 1903
| Athletic Bilbao|
| Juan Astorquia
Alejandro de la Sota (2 goals each)|
1944–45 Copa del Generalísimo
The Copa del Rey 1903 was the first official edition of the Copa del Rey. It followed the 1902 Copa de la Coronación, held to celebrate the coronation of King Alfonso XIII of Spain, which was won by Club Vizcaya de Bilbao (a temporary combination of Bilbao FC and Athletic Bilbao) and given to them permanently.
1903 Copa del Rey Wikipedia
The competition was played on April 6, 7 and 8, 1903. Three teams took part: Athletic Bilbao, Espanyol of Barcelona and Madrid CF. It took the form of a round-robin, but the results of the first two games meant that the third game became the final. That match, held at the Hipódromo in Madrid, saw Athletic Bilbao take the trophy for the first time as a distinct club, beating Madrid 3‑2 after trailing 2‑0 at half time. As a result, the tally of Copa wins by Athletic Bilbao is disputed. The 1902 cup, won by Club Vizcaya, is on display in the Athletic museum, and the club includes the victory in its honours list. However, neither the Liga de Fútbol Profesional (LFP) nor the Real Federación Española de Fútbol (RFEF) official statistics include this as an Athletic win: they count the 1903 cup as its first.