Argentina skipper Lionel Messi was sent off late in the first half together with Chile’s Gary Medel after the pair had clashed following a Messi challenge.
That flashpoint came after Messi had set Aguero up for La Albiceleste’s opening goal on 11 minutes, his superb through-ball finding the perfectly timed run of Aguero who finished in customary lethal fashion.
With Chile talisman Alexis Sanchez then forced off with a hamstring injury, Argentina struck again on 22 minutes through Juventus midfielder Pablo Dybala who beat Chile keeper Gabriel Arias with an exquisite lob from an acute angle.
The game then erupted in controversy on 36 minutes when both Messi and Medel were shown the red card after a VAR check following an encounter between the pair.
Former Cardiff defender Medel, now of Besiktas, angrily reacted to a challenge by the Barcelona icon as the ball went out of play and the pair were subsequently both dismissed by referee Mario Diaz de Vivar
There was no let-up in the intensity after the break and Chile gained a foothold in the game via a 59th minute penalty, awarded via another VAR check, which was converted by Arturo Vidal.
With 14 minutes left Aguero almost struck again after good work by Angel di Maria but Arias saved the City man’s deft chip. Aguero then sent an effort just wide before being substituted as Argentina held firm to seal third place.
Attention at the South American showpiece now switches to Sunday’s final which sees hosts Brazil take on Peru.