FC Porto the 1955–56 Primeira Divisão on head-to-head advantage over runners-up Benfica. Later that season, Porto beat Torreense to win its first Taça de Portugal and achieve its first double. As the Portuguese league winner, Porto made its debut in European competitions by qualifying for the 1956–57 European Cup. The club's first participation was short-lived, ending in the preliminary round with two defeats against Spanish champions Athletic Bilbao. A year later, Porto lifted its second Taça de Portugal by beating Benfica 1–0 in the final. The two clubs met again in the following season's final, but this time Benfica took the trophy
1974–75 S.L. Benfica season first but drew the others. First with Sporting on the 22, for the Derby de Lisboa, and then on the 29, with União de Tomar. Benfica lapped the first half of the season in second place with three points less than leaders Porto. In January, Benfica won their opening match, while Porto lost theirs, reducing the gap between them to a point. Two weeks later, Benfica defeated Olhanense on the road and Porto lost in Alvalade, with the teams exchanging places. Benfica now led by a point over Porto. In the last match of the month, Benfica defeated Leixões at