A three-goal first half led Colo Colo to a 4-0 thrashing of Antofagasta at the Estadio Monumental David Arellano.
It marked Colo Colo's third straight win, a run which has included nine goals without conceding.
Their latest win started in the 26th minute as Esteban Paredes put away a penalty after Felipe Flores was fouled in the area.
Jean Beausejour doubled the advantage six minutes later, getting on the end of a long pass and finishing into the bottom corner.
Juan Delgado finished clinically just before half-time, chipping the advancing Pablo Aurrecochea.
Just after the break, the contest was over.
Jaime Valdes capped off a fine team move by drilling a 30-yard effort into the bottom corner.
But Universidad Chile stayed three points clear thanks to a 1-0 win at Union Espanola as Gustavo Canales scored a 78th-minute goal.
Santiago Wanderers dropped points, thrashed 4-0 by a Lucas Simon-inspired Huachipato.
Simon struck twice in the first half and once in the second as Huachipato joined Wanderers on 13 points.
Kevin Harbottle scored a 90th-minute winner to see San Marcos to a 1-0 victory over Palestino.
Octavio Rivero's brace helped O'Higgins draw 2-2 at Universidad Catolica and Union La Calera and Universidad Concepcion drew 1-1.
Cobresal edged Cobreloa 2-1, Deportes Iquique left it late to beat Barnechea 1-0 and Nublense were 1-0 winners at Audax Italiano.
