Porto maintain advantage

The reigning champions took the lead in the ninth minute as Brazilian striker Adriano netted for the third time in the league this season and hung on despite a concerted effort from the fourth-place team.

Their closest challengers remain Benfica after they recorded an identical victory over bottom side Desportivo Aves.

The Lisbon giants dominated proceedings and were worth much more than their 1-0 win, which was down to a brilliant strike from Nuno Gomes, the Portugal striker who scored for the sixth time this season.

The third of Saturday's games saw surprise high-flyers Pacos de Ferreira beating Vitoria Setubal 1-0.