F.C. Lisbonense
In 1894 King Carlos I created a national cup, to be played annually for the football championship of the cities of Portugal.Only one edition was played, in 1894, when F.C. Porto lost 0-1 to F.C. Lisbonense (predecessors of CIF-Clube Internacional de Futebol).
One version of the history of FC Porto is that wine merchant António Nicolau de Almeida founded the club in 1893. Nuno Dias' helpful comments below share some information that I didn't know when I originally wrote the post .
The club that evolved into Sporting Clube de Portugal has its origins in 1902; a game played by aristocratic young men during a holiday. They styled themselves Sport Club de Belas (Belas being the location of their vacation). After the holiday was over they returned to the Lisbon suburb of Campo Grande and decided to continue their footballing activities. In 1904 they founded Campo Grande Football Club. Conflict between the genuine sport enthusiasts and those more interested in social events led to a schism. In 1906 the sporting wing became Campo Grande Sporting Club.
Sporting's first official fixture was played on 3rd February 1907.
Benfica
Founded in the Belém neighborhood of Lisbon on February 28th, 1904 as Grupo Sport Lisboa. In 1908 the merged with Sport Clube de Benfica (founded in 1904) and took the name Grupo Sport Benfica. Members of Grupo Sport Lisboa kept the football side of the club alive.
In October, 1908, a month after the merger, the club won its first game ever against Sporting.