Rodrigo Lopez and Jorge Recalde struck braces for Libertad as they claimed a convincing 4-1 victory over 3 de Febrero.
Pedro Sarabia's men have won six of their opening seven league games – the other ending in a draw – to open up a four-point gap at the top.
Nacional Asuncion have a game in hand and are second after a hard-fought 2-1 win at home to Sol de America on Monday.
At Libertad's Estadio Dr Nicolas Leoz, the league's leading goalscorer Lopez needed just four minutes to put the hosts ahead.
Lopez tapped in the easiest of opening goals from yards out after a corner went over a group of players who moved towards the front post.
They had to wait until the 49th minute to double their advantage as Recalde tapped in the second goal of the game from close range.
The visitors pulled back to within a goal three minutes later thanks to Jose Caceres' header.
But Recalde's header on 54 minutes restored Libertad's two-goal advantage and Lopez completed the scoring with a neat finish soon after for his ninth strike of the campaign.
Nacional Asuncion were pushed harder before overcoming Sol de America, who suffered their first loss of the league campaign.
Julian Benitez and Christian Ovelar traded first-half goals, only for Julio Santa Cruz to score the winner on 71 minutes.
Elsewhere, third-placed Guarani had no problems in a 3-0 win over Cerro Porteno and Olimpia were held to a 1-1 draw at home to 12 de Octubre.
A 10-man Sportivo Luqueno held on for a 1-1 draw at home to Deportivo Capiata and General Diaz came from behind to draw 1-1 against Rubio Nu.
