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
1978–79 S.L. Benfica season handed the title to Porto, who gained a point with one match left. A week later, Benfica won, but so did Porto, who confirmed their back-to-back league title with 50 points, one more than Benfica. About the season, Mortimore said: "What a beautiful championship, with an appealing fight between Benfica and Porto. They (Porto) ended up being Champions because in the matches against us, they racked-up three points. But that was not the reason why he lost it. It was the poor results with Belenenses, Setúbal and Marítimo.". Two seasons without any honour was not seen since 1948, and two