Joao Moutinho scored the only goal of the first leg as FC Porto took control of their Champions League tie against Malaga.
In a tight opening to the contest, neither side was able to enjoy any sustained periods of possession.
Malaga were not providing much of an attacking threat in the first period and were lucky to remain on level terms when Silvestre Varela headed Moutinho's cross wide of the post.
The visitors looked solid in defence but as the first half drew to a close, Porto started to take control in midfield.
Porto continued to apply the pressure after the break and broke the deadlock in the 56th minute when Moutinho found space inside the area to calmly slot the ball home.
The hosts grew in confidence following the goal and went in search of a second while Malaga continued to struggle in attack, with Roque Santa Cruz looking an isolated figure up front.
In the end, Porto cruised to a crucial victory, controlling possession with ease against their Spanish opponents in front of a delighted Portuguese crowd.