Mario Salas' Huachipato extended their unbeaten league run to six matches with a resounding 6-0 win over Union La Calera at the Estadio Municipal Nicolas Chahuan Nazar.
The run has lifted Huachipato, who had a dreadful Apertura campaign, clear of the relegation zone and into sixth in the Clausura.
Union La Calera are only outside the bottom two in the aggregate table on goal difference, despite the six-goal hammering, ahead of the final matchday of the season.
David Llanos headed in a fifth-minute opener for visiting Huachipato before their lead was doubled soon after.
Felipe Reynero netted a scrappy second before Jose Contreras' smart header looped over goalkeeper Juan Ojeda to make it 3-0.
Llanos tapped in a cutback moments before the break to make it 4-0 at half-time.
The fifth goal, on 71 minutes, came via Francisco Arrue from the penalty spot before Llanos completed his hat-trick.
Rangers' relegation was confirmed after a 2-0 loss to fellow strugglers Audax Italiano.
Audax Italiano are a point clear of second bottom Everton, who came from behind to take a point in a 1-1 draw at home to Nublense.
Sebastian Varas opened the scoring early in the second half before Carlos Ponce levelled on the hour-mark.
Santiago Wanderers are safe after overcoming Cobresal 2-0 thanks to two late goals.
Clausura champions Colo Colo gave up two leads as they were held to a 2-2 draw by second-placed Universidad Catolica and O'Higgins were 3-1 winners at Union Espanola.
Elsewhere, Deportes Iquique claimed a 1-0 win at Palestino, Universidad Concepcion overcame a Universidad Chile side that finished with eight men 1-0 and Antofagasta edged Cobreloa 1-0.
