Benfica moved to the top of Liga Sagres with a 3-1 win over Lisbon rivals Sporting, while Sporting Braga defeated lowly Academica on Monday.
Two goals from Oscar Cardozo guided Benfica to victory at Sporting, who slumped to their worst start since the league was established in 1933.
Sporting opened the scoring through Ricky van Wolfswinkel in the 31st minute but came undone in the second half.
Cardozo managed to reach Ola John’s cross into the box just before the hour mark, but the final touch came from Sporting defender Marcos Rojo, who levelled proceedings with an own goal.
The hosts were dealt a further blow on 80 minutes when Khalid Boulahrouz used his hand to stop Eduardo Salvio’s shot on the line.
Boulahrouz was sent off before Cardozo put Benfica ahead from the resultant penalty.
Cardozo sealed the win with a powerful header four minutes from time, although replays suggested the ball might have taken a key deflection off Sporting defender Emiliano Insua.
Benfica are on top of the table with 29 points, marginally ahead of Porto, who have the same amount of points but have scored one less goal.
Meanwhile, goals from Ismaily, Ruben Amorim, Marcio Mossoro and Carlao led Braga to a 4-1 win at Academica.
Salim Cisse scored a late consolation for the hosts, who dropped into the relegation zone with just nine points from 11 matches.