S.L. Benfica 2015, Benfica reported to have 246,401 members; however, after a scheduled renumbering by the club in August 2015, the number decreased to 156,916. In April 2017, Benfica reported they had a total of 184,264 members by 31 December 2016. Benfica has rivalries with Sporting CP and FC Porto, with whom it forms the "Big Three": Portugal's most decorated clubs. None of them have been relegated from the Portuguese league since its establishment in 1934. As Lisbon-based clubs, Benfica and Sporting have shared a rivalry for over a century; it all started in 1907 when eight prominent Benfica players defected to
1972–73 S.L. Benfica season from Eusébio. With the win, Benfica opened a two-point lead over their rivals. They continued on their winning run, beating Belenenses at home by 5–0 on match-day 7. With seven wins in seven matches, their lead was now three points. Back on the European stage, Benfica visited Baseball Ground to face Derby County on 25 October. Three first-half goals from Derby County surprised Benfica, who failed to react and lost 3–0. Before the second leg, Benfica played the Clássico with Porto for the Primeira Divisão. Porto scored first and was winning by 2–0 until the 78th minute, when Benfica scored