Leonardo Astrada's Cerro Porteno coughed up a lead at Deportivo Capiata in a 1-1 draw on Saturday.
Oscar Romero's goal gave the leaders the upper-hand in the 37th minute in Capiata but Dario Lopez Torres drew the hosts level in the first minute after the interval.
It was the second time in as many matches Cerro Porteno had coughed up a lead to draw but Guarani failed to capitalise as they also chalked up successive stalemates.
Guarani had to fight back late to draw 2-2 at Sportivo Luqueno last time out but failed to trouble the scorers at home to Nacional Asuncion in a 0-0 draw.
The lacklustre results from Paraguay's top two saw Libertad (third, 24 points) move within three points of leading Cerro Porteno courtesy of their 6-0 rout of General Diaz.
Libertad drove in three goals in each half, with Juan Santacruz earning a brace, as they sauntered to their seventh win of the season and extended their unbeaten streak to four games.
Consecutive wins to 12 de Octubre saw them further climb the table, the once-bottom club now five points clear of the basement after a 2-0 road win over 3 de Febrero.
Juan Abente and Gustavo Santacruz struck five minutes apart late on, to earn 12 de Octubre's fourth win of the campaign and move them within six points of Olimpia in fourth.
Olimpia's poor run continued, making it five games without success as they were held 1-1 by Sportivo Luqueno.
Bottom two clubs Rubio Nu and Sol de America cancelled each other out in a 1-1 stalemate on Friday.
