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
1970–71 S.L. Benfica season put Sporting and Benfica level on points. Benfica closed March with an away win over Leixões, with Porto losing and dropping out of race. This left Benfica and Sporting with a three–point lead and three match-days to go. On 4 April, Benfica beat Vitória de Setúbal at home and for the first time headed the league isolated, with a two-point lead. Sporting had lost with Porto. Three weeks later, Benfica confirmed their league title with an away win over Varzim. It was their 18th league title. They finished the Primeira Divisão with a 5–1 victory over Académica, ending the campaign