A day after Libertad claimed a 2-0 win at 12 de Octubre, Cerro Porteno went down 1-0 at Sportivo Luqueno.
The results saw Libertad go two points clear at the top with two Clausura matches remaining this campaign.
On Sunday, first-half goals from Juan Danilo Santacruz and Nestor Camacho helped Libertad to their win at the Estadio Juan Canuto Pettengill.
Santacruz struck first in the 33rd minute, cutting in from the left and skipping past two defenders before finishing into the bottom corner.
Camacho scored seven minutes later from an angle, and that was all Pedro Sarabia's men needed to put the pressure on Cerro Porteno.
And Cerro Porteno were unable to respond, with Guido Di Vanni's 46th-minute goal seeing them lose at Sportivo Luqueno.
Di Vanni guided a cross into the bottom corner just after half-time for the hosts.
Guarani are five points off top spot, but did enjoy a 4-2 win at home to General Diaz.
Federico Santander and Fernando Fernandez netted braces for the victors, who had coughed up a 2-0 lead.
Also on matchday 20, 3 de Febrero had a 2-1 win over Deportivo Capiata.
Olimpia and Rubio Nu finished 0-0, while the clash between Nacional Asuncion and Sol de America also ended up goalless.
