Leading the Clausura table by seven points heading into their clash at Carapegua's Estadio Teniente Coronel Antonio, Cerro Porteno knew a win would not only seal top spot and the title, but also a Copa Libertadores berth for next season.
However, Francisco Arce's men failed to trouble the scorers, although they still hold an eight-point buffer on closest rivals Deportivo Capiata with three games to play.
Capiata kept their chances of finishing first alive, with a 1-0 home win over Nacional Asuncion on Saturday.
Julio Irrazabal scored the winner for Capiata, who must win all three of their matches in the run-in to stand any chance of stealing top spot off Cerro Porteno.
Helping their cause is one of those fixtures is between the top two teams, meaning a Cerro Porteno slip up against third-placed Libertad combined with a Capiata victory over fourth side Guarani next week would set up a tantalising penultimate clash of the season.
Guarani moved within two points of Libertad with a 2-0 win on the road over them on Sunday, with Ramon Ocampo and Fernando Fernandez scoring the goals.
General Diaz are winless in seven - on the back of their 15-match unbeaten streak - after a 3-0 loss away to Cerro Porteno PF, leaving them sixth on the table.
Cerro Porteno PF still remain bottom of the league on 16 points, but have Olimpia (19), Carapegua (18) and Sol de America (17) in their sights.
In other results, Rubio Nu had a 1-0 road win over Sportivo Luqueno, while Olimpia were held to a 2-2 draw at home to Sol de America.
