Jorge Jesus' men are unbeaten in 21 league games and seven points clear at the summit after beating fourth-placed Estoril 2-0.
Two early goals proved decisive for Benfica, with Brazilian centre-back Luisao opening the scoring after seven minutes and Rodrigo adding a second 13 minutes later.
While Benfica have recorded five wins in succession, Sporting's run of three straight victories came to an end with a 2-2 draw at Vitoria Setubal.
The visitors took the lead through Islam Slimani's 34th-minute strike, only for Rafael Martins to respond early in the second half.
Adrian Silva looked to have given Sporting all three points when he converted a penalty with four minutes remaining.
Yet there was still time for Setubal to be awarded a spot-kick of their own, which Ricardo Horta converted to rescue a point.
Porto closed to within two points of Sporting and kept their slim title chances alive with a 4-1 victory over Arouca, who are now only two places above the relegation zone.
In Luis Castro's first game as temporary coach following the departure of Paulo Fonseca, Porto were sent on their way by Ricardo Quaresma’s 11th-minute penalty.
Carlos Eduardo added a second prior to Rui Sampaio reducing Arouca's arrears, and Porto then made the game safe late on with another goal from Quaresma and Jackson Martinez's 15th of the season.
Belenenses, who sit 14th, are without a win in five games following a 0-0 draw with Olhanense, the team immediately below them in the table.
Gil Vicente moved eight points clear of the drop zone and inflicted a 14th defeat of the season on bottom side Pacos De Ferreira with a 2-0 away success.
