Marvin Solano's Herediano were taught a football lesson by defending champions Alajuelense midweek, crashing to a 5-2 defeat on the back of an Armando Alonso hat-trick at the Estadio Alejandro Morera Soto.
But Deportivo Saprissa's 1-1 draw at Puntarenas opened the door for Herediano, who responded with an emphatic 3-0 victory over struggling Cartagines.
Herediano made a bright start to proceedings and were awarded a 27th-minute penalty, which was coolly converted by veteran attacker Minor Diaz.
The home side continued to peg away at Cartagines but had to wait until six minutes into the second half to double their advantage, with Olman Vargas heading home his first goal of the campaign.
Vargas was on target again two minutes from time, leaping highest to guide the ball home as Herediano made it five wins in succession on home soil.
The result saw Herediano move to 33 points alongside Saprissa but ahead on number of goals scored.
Elsewhere in Costa Rica, Alajuelense remain five points off the pace in third position after claiming a routine 2-0 win over Santos de Guapiles.
Alajuelense made a dream start at the Estadio Ebal Rodriguez Aguilar, with Jorge Davis breaking the deadlock inside the opening minute.
Camilo Aguirre put the result beyond seven minutes into the second half - his second goal in the space of a week.
Belen Siglo XXI continued their rise up the table, stunning Carmelita 2-1 thanks to first-half goals from Allan Duarte and Jose Varela.
Vinicio Alvarado's men are now five points adrift of the top four following back-to-back wins.
In other results, Uruguay bounced back from their midweek defeat with a hard-fought 1-0 triumph at home to basement club Perez Zeledon, while Diego Diaz converted a 50th-minute penalty as Limon earned a 1-1 draw against UCR.
