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
1986–87 S.L. Benfica season campaign started with a Clássico with Porto, which ended with a draw. A win in match-day 2 was followed by another draw. Six consecutive wins propelled Benfica into first place isolated, with two points in hand. In the end of November, Benfica contested the Supertaça with Porto and was defeated by 4–2 at home, after a one-all draw in Antas. On the second week of December, in the Derby de Lisboa with Sporting, Benfica conceded their largest loss ever in the Primeira Divisão, losing 7–1. Fans reacted with anger towards Mortimore and ripped flags and scarfs with the club image.