Porto put pressure on Primeira Liga leaders Benfica ahead of the Lisbon derby by cutting the gap at the top to three points with a 2-0 win at Moreirense on Saturday.
Defending champions Benfica visit arch rivals Sporting Lisbon on Sunday in what will be a crucial match in the three-horse race between Portugal's most famous footballing institutions.
And Porto ensured that they will at most be just six points behind Jorge Jesus' men with a comfortable victory.
Jackson Martinez put Porto ahead in the 28th minute with his 24th goal of the season, the Colombian collecting a ball from the left and converting from close range.
And Julen Lopetegui's men made sure of the points when on-loan Real Madrid midfielder Casemiro scuffed home at the far post in the 59th minute.