Porto and Benfica leapfrogged Sporting Lisbon at the top of the Primeira Liga table by securing victories on Friday.
Paulo Fonseca's Porto side had few problems in brushing aside strugglers Olhanense 4-0 at Estadio do Dragao.
Eliaquim Mangala's strike gave the hosts a slender lead at the break.
Olhanense, who have won just twice this season, were completely over-run in the second half as Jackson Martinez, Carlos Eduardo and Hector Herrera all got their names on the scoresheet.
The victory sends Porto to the top of the table, although Sporting can reclaim top spot by beating Nacional on Saturday.
Olhanense remain in the relegation zone as a result of their fifth straight league defeat.
Benfica stayed level on points with Porto courtesy of a 2-0 success at 11th-placed Vitoria Setubal.
Jorge Jesus' men were frustrated in their efforts to break the deadlock in the first half at Estadio do Bonfim.
However, Benfica found the breakthrough when Rodrigo notched in the 54th minute.
The result was confirmed on 69 minutes as Lima made it 2-0 from the penalty spot.