Paredes, who plays for Italian Serie A side Reggina, scored in the 31st minute to put Paraguay top of the South American zone standings, at least until Brazil and Argentina play on Wednesday.
Paraguay, attempting to reach their third successive World Cup finals with a squad based largely on the players who qualified in 1998 and 2002, have nine points from four games.
They are two points ahead of Brazil and Argentina, who play their fourth games on Wednesday, at home to Uruguay and away to Colombia respectively. Chile, who missed out in 2002, have four points from four games and are seventh in the standings.
Paraguay's goal came from one of their typical aerial attacks with right-back Francisco Arce almost inevitably the instigator.
Arce floated one of his trademark crosses into the penalty area, Jose Cardozo headed down at the far post and Paredes scored with a first-time shot from the edge of the box which took a deflection off Chile's Rafael Olarra.
Paraguay packed their defence for the second half and, despite ample possession, hosts Chile lacked the inspiration to find a way through.
They won a number of free kicks in good positions but most were struck straight into the wall by David Pizarro.
Striker Mauricio Pinilla had Chile's best chances. In the first minute, he burst into the Paraguay area but his shot was blocked by goalkeeper Justo Villar.
Pinilla also shaved the crossbar with a header in the first half and the post after he again outjumped the defence in the 61st minute.
The game was marred by an ugly flare-up in the second half but lenient Uruguayan referee Gustavo Mendez did not show a yellow card.
