S.L. Benfica Sporting. Followed in Europe, Africa and the Americas, any match between both teams is known as "dérbi de Lisboa" ("Lisbon derby"), "dérbi eterno" ("eternal derby"), "dérbi da Segunda Circular", "dérbi dos dérbis" ("derby of the derbies") – the most important football derby in Portugal. The rivalry between Benfica and FC Porto, which started with a friendly match on 28 April 1912, comes about as Lisbon and Porto are the largest Portuguese cities, respectively. Benfica and Porto are currently the two most decorated clubs in Portuguese football, with the former historically being the most decorated team overall. Any match between the
1990–91 S.L. Benfica season attentions were pointed on the league title. A strong campaign witnessed Benfica overtake Porto in February and then close the title with an away win in the Clássico, a controversial match because of the tactics employed by Porto to destabilize the team. On late May, Benfica secured their 29th league title, while Rui Águas won the Bola de Prata for league top-scorer. Benfica started the new season after having lost their fifth European Cup Final in the past season, while Porto regained the league title back. Swedish manager Sven-Göran Eriksson made some squad adjustments, releasing established players like Fernando Chalana,