The 1921–22 season was marked by the creation of the first nationwide football competition – the Campeonato de Portugal. Organised by the national federation, this knockout tournament gathered the winners of the regional championships to determine the Portuguese champion. After clinching its fourth consecutive regional title, Porto defeated Sporting CP in the inaugural edition and became the first national champions. While a dominant regional force, the club faced stronger opposition in the national championship, winning it only three more times in a span of sixteen years (1925, 1932 and 1937). In 1933–34, Porto was denied participation in the Campeonato de Portugal by its football association for refusing to release players for a match between the Porto and Lisbon regional teams.