Second-placed FC Porto could only manage a goalless draw at Paços de Ferreira to allow the defending champions to move clear at the top.
Sporting meanwhile beat Feirense 2-1 in Lisbon, to remain fourth-place.
In the Second Division, Portimonense and Desportivo das Aves are clear favourites to gain promotion after winning once more over the weekend.
Leaders Portimonense moved 17 points clear of third-placed Santa Clara who they beat 1-0 in Portimão, while Aves won 2-1 at Fafe.