[1] A total of 16 teams competed in the final stages to decide the champions of the 2018 Copa Sudamericana.
[3][4] Tied 0–0 on aggregate, Santa Fe won on penalties and advanced to the quarterfinals (Match S1).
Tied 1–1 on aggregate, Atlético Paranaense won on penalties and advanced to the semifinals (Match F2).
In the finals, if tied on aggregate, the away goals rule would not be used, and 30 minutes of extra time would be played.
If still tied after extra time, the penalty shoot-out would be used to determine the winner (Regulations Article 28).