The 2018 Copa Sudamericana final stages were played from 21 August to 12 December 2018.[1] A total of 16 teams competed in the final stages to decide the champions of the 2018 Copa Sudamericana.[2]
Qualified teams
The 16 winners of the second stage advanced to the round of 16.
Seeding
Starting from the round of 16, the teams were seeded according to the second stage draw, with each team assigned a "seed" 1–16 corresponding to the tie they win (O1–O16) (Regulations Article 22.c).[2]
Each tie was played on a home-and-away two-legged basis, with the higher-seeded team hosting the second leg (Regulations Article 22.d).
In the round of 16, quarterfinals, and semifinals, if tied on aggregate, the away goals rule would be used. If still tied, extra time would not be played, and the penalty shoot-out would be used to determine the winner (Regulations Article 27).
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).
Bracket
The bracket starting from the round of 16 was determined as follows:
Round
Matchups
Round of 16
(Higher-seeded team host second leg)
Match A: Winner O1 vs. Winner O16
Match B: Winner O2 vs. Winner O15
Match C: Winner O3 vs. Winner O14
Match D: Winner O4 vs. Winner O13
Match E: Winner O5 vs. Winner O12
Match F: Winner O6 vs. Winner O11
Match G: Winner O7 vs. Winner O10
Match H: Winner O8 vs. Winner O9
Quarterfinals
(Higher-seeded team host second leg)
Match S1: Winner A vs. Winner H
Match S2: Winner B vs. Winner G
Match S3: Winner C vs. Winner F
Match S4: Winner D vs. Winner E
Semifinals
(Higher-seeded team host second leg)
Match F1: Winner S1 vs. Winner S4
Match F2: Winner S2 vs. Winner S3
Finals
(Higher-seeded team host second leg)
Winner F1 vs. Winner F2
The bracket was decided based on the second stage draw, which was held on 4 June 2018.
Template:16TeamBracket-2Leg
Round of 16
The first legs were played on 21–22 August, 18–20 and 26 September, and the second legs were played on 19, 25, 27 September, and 2–4 October 2018.[3][4]
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).[2]
The first leg was played on 5 December, and the second leg was played on 12 December 2018.