1983–84 S.L. Benfica season left the club in second, a point shy of the leader Porto, their next opponent. In the Clássico, Benfica beat his rival Porto and assumed first place. Later in the month, Benfica defeated Olympiacos in the second round of the European Cup, qualifying for the quarter-final. In November and December, Benfica won all their league matches, but lost the Supertaça Cândido de Oliveira to Porto. Benfica kept on winning in the Primeira Divisão in January, lapping the first part of league with a three-point lead. However they suffered a set-back in the Taça de Portugal, losing 2–1 in Estádio de
1984–85 S.L. Benfica season won all league matches in April. In the Supertaça Cândido de Oliveira, a one-nil win for both Benfica and Porto forced a replay of the competition. In early May, John Mortimore was confirmed as new manager, with Csernai still in charge for another month. Before the end of May, Benfica lost away in the first leg of the Supertaça to Porto, but won the Derby de Lisboa with Sporting by 3–1, reducing the distance between them. In June, Benfica lost again in the Supertaça, losing the competition and finished the league in third place, 12 points behind Porto and five