Benfica extended its overnight lead of the Portuguese league to five points through its 2-1 win at Feirense on Saturday.
Fernando Varela headed in Feirense's 50th opener, but four minutes later the defender leveled the score with an own goal when he headed an attempted clearance into his team's net.
Oscar Cardozo stroked home the winner for Benfica from the penalty spot in the 73rd after Varela fouled Rodrigo Moreno. It was Cardozo's league-leading 13th goal of the season.
Also, Academica drew 0-0 at Rio Ave.
Second-placed Porto will look to keep pace with Benfica when it visits Gil Vicente on Sunday.