Andre Andre struck an 86th-minute winner as Porto left it late to beat bitter Primeira Liga rivals Benfica 1-0 at the Estadio do Dragao tonight.
The visitors started the better of both sides and would have moved ahead after eight minutes if not for Iker Casillas, who pulled off a smart stop to keep out Konstantinos Mitroglou.
The on-loan Fulham defender was denied by the ex-Real Madrid goalkeeper again three minutes later as Benfica dominated the opening stages.
Both sides cancelled each other out for much of the half, but Miguel Layun almost drilled Porto ahead when his effort whistled wide of the mark shortly before the break.
Julen Lopetegui's side came within inches of moving ahead early in the second half when Vincent Aboubakar crashed his header against the post in a huge let-off for Benfica.
Aboubakar grew more dangerous as the half went on, and latched on to a through-ball from Andre before firing wide of Julio Cesar's goal.
It proved a sign of things to come, though, as Andre stroked home the winner with four minutes remaining to snatch all three points.