The 2012 Apertura champions scored the opener five minutes before half-time when Julio Dos Santos converted from the penalty spot.
Diego Godoy doubled Cerro Porteno's advantage in the 58th minute before Rodrigo Lopez's penalty pulled a goal back for Sportivo on 64 minutes.
But the home side could not find an equaliser and Cerro Porteno now move four points clear on top of the table - ahead of other unbeaten side General Diaz, who won 1-0 against Sol de America.
An unfortunate own goal from Sol de America's Hugo Rafael Baez secured the three points for Diaz.
Baez was also given his marching orders for a second bookable offence in stoppage time.
A 25th-minute strike from Dionisio Perez handed Deportivo Capiata a 1-0 triumph at strugglers Cerro Porteno PF.
It was Cerro Porteno PF's fifth loss from six league games as they remain rooted to the bottom of the table.
Rubio Nu managed to overcome Olimpia 2-0 despite the disadvantage of playing 42 minutes a man down.
After scoring Rubio's first goal on 10 minutes, striker Francisco Vera received his second yellow card in the 48th minute.
Olimpia pushed hard for the equaliser but Osvaldo Hobecker wrapped up the victory for Rubio eight minutes from time.
Deportivo Carapegua salvaged a 2-2 draw against 10-man Guarani with an 89th-minute goal from Serginho.
Carapegua led 1-0 when Guarani substitute Federico Santander was given two yellows in the 59th minute - only five minutes after entering the field of play.
Even with the disadvantage, Guarani scored twice and looked set for an unlikely victory until Serginho's late effort.
The clash between Libertad and Nacional Asuncion was postponed.
