Futebol Clube do Porto , MHIH , OM [ 1 ] [ 2 ] ( Portuguese pronunciation: [futɨˈβɔl ˈkluβɨ ðu ˈpoɾtu] ), commonly known as FC Porto , Porto , or FCP is a Portuguese professional sports club based in Porto . It is best known for the professional football team playing in the Primeira Liga , the top flight of Portuguese football .