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
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.