A second-half brace from Carlos Saucedo was the catalyst behind Saprissa's crushing 4-0 victory at the Estadio Ricardo Saprissa Ayma.
Saprissa, who have not lost since the opening day of the season, are five points clear at the summit having collected 46 points from 21 games, while sixth-placed Belen Siglo XXI were condemned to back-to-back losses.
Ronald Gonzalez Brenes' men did not have to wait long for a second goal, with veteran striker Saucedo doubling their advantage seven minutes into the second half.
Youngster David Ramirez got in on the action, netting Saprissa's third on 83 minutes before Saucedo capped a dominant performance with an injury-time penalty.
Ariel Rodriguez's 33rd-minute penalty was all that separated the two teams at the Estadio Eladio Rosabal Cordero.
