In the final game of the Clausura phase - which Colo Colo had already wrapped up - Paredes almost doubled his season tally in 90 minutes.
Paredes finished the season with 11 goals, after twice helping Colo Colo regain the lead in a thrilling contest at Nublense's Estadio Bicentenario Municipal Nelson Oyarzun.
Jose Rojas opened the scoring for Nublense on 22 minutes, but Paredes had Colo Colo ahead by half-time as he entered the dressing rooms on a hat-trick.
Sebastian Varas drew Nublense level 10 minutes into the second half, but Paredes' response was emphatic - putting Colo Colo back ahead a minute later.
Paredes' fourth - a penalty - came eight minutes later, although Nublense did not go away, as Varas' second ensured a nervous finish.
The man of the moment sealed the three points for Colo Colo, with his fifth on 82 minutes wrapping up a dazzling 43-minute blitz.
Joining Colo Colo in the play-offs are Universidad Catolica (33 points), O'Higgins (30), Universidad de Concepcion (27) and Palestino (26).
Universidad de Concepcion shattered Deportes Iquique's hopes of reaching the finals, beating the top-five aspirants 1-0 on the road to climb into fourth.
Michael Lepe's 65th-minute goal turned out to be the winner, and Concepcion held on despite losing Francisco Portillo to a red card with eight minutes to play.
Huachipato could not break down Everton as they limped to a 0-0 draw that ended their hopes of progressing into the next phase.
Palestino earned fifth place, with a 1-1 draw at Audax Italiano.
Given Huachipato and Deportes Iquique slipped up, Palestino did not need a point from the clash, but earned one via Marcelo Morales' 85th-minute equaliser.
Cobreloa finished the season on a high, thrashing Universidad Chile 4-0 away from home.
Cobresal were 2-0 winners over Union Espanola, who lost four of their past five to miss the top-five spots by just three points.
Antofagasta came from behind to earn a 1-1 draw at home to Santiago Wanderers, while Universidad Catolica overcame a first-minute concession to draw 1-1 with Union La Calera.
O'Higgins denied Rangers' attempt to avoid finishing bottom of the table, equalising late for a 1-1 draw against them.
