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
1983–84 S.L. Benfica season Alvalade being eliminated by Sporting. In February, Benfica lost points again in the league after twelve consecutive wins. March was even more troublesome because the team was knocked-out of the European Cup by Liverpool, while in the league, Porto gave them their first league loss all season. Still, in the following month, Benfica won five games and draw one, allowing them to keep the three point lead over Porto. On 29 April, Benfica unexpectedly lost 4–1 with Vitória de Guimarães. The loss did not cause major damage because Porto had also lost points, so the distance was only cut to