The big 3 in Portugal is Benfica (31 titles), Porto (22 titles), and Sporting Lisbon (18 titles). They have won all but 2 league titles. Belenenses won the league in 1946 , and Boavista won it in 2001. In spite of this, Vitoria Guimaraes is considered to be the “fourth” club in the country, owing to their sizable support. They were relegated in 2006, but bounced right back up last season.
Portugal’s domestic league is good enough to get them up to 3 spots each year in the Champions League. Portugal’s current national league ranking by UEFA is #6 in Europe.