Michael Rios and Ismael Sosa struck in the final 11 minutes for Universidad Catolica, who recorded a 2-0 win over Santiago Wanderers.
It saw them stay two points clear at the top as O'Higgins, Cobresal and Universidad Chile all secured wins.
Pablo Hernandez's 45th-minute goal was all O'Higgins needed at Universidad Concepcion to clinch a 1-0 win.
Cobresal also claimed a 1-0 win but left it much later as Alvaro Navarro struck five minutes before full-time to see his side edge past Huachipato and stay four points adrift.
Universidad Chile were the most convincing of the top four in their 3-0 victory at Deportes Iquique.
Charles Aranguiz was on the scoresheet once in each half before Isaac Diaz completed the scoring on 80 minutes.
Cobreloa have fallen six points behind the league leaders after a third straight loss, beaten 2-1 at Colo Colo.
Felipe Flores' 90th-minute goal gave Colo Colo their second consecutive league win and saw Cobreloa slip to fifth.
Union Espanola came from behind to beat Palestino 2-1 and Union La Calera were 2-0 victors at home to Everton.
Rangers ended their six-match winless run with a 2-0 win at Antofagasta and Nublense secured a 2-0 win at Audax Italiano.
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