Porto go top after Benfica and Sporting stumble
The champions reached the halfway mark of the season on 31 points, a point clear of Benfica and Sporting.
Benfica, who drew 0-0 at Belenenses on Friday, and Sporting, held to a 1-1 draw at Nacional Madeira on Saturday, have 30 points each from 15 matches.
Uruguayan winger Cristian Rodriguez put Porto in front with a volley following a goalmouth scramble after 20 minutes.
Argentine striker Lisandro Lopez doubled the lead when he collected a long pass by Hulk and finished calmly in the 31st.