2018 Copa Sudamericana final stages

The 2018 Copa Sudamericana final stages were played from 21 August to 12 December 2018. A total of 16 teams competed in the final stages to decide the champions of the 2018 Copa Sudamericana.

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 .

Seed

Match

Second stage winners

Format

Starting from the round of 16, the teams played a single-elimination tournament with the following rules:

Each tie was played on a home-and-away two-legged basis, with the higher-seeded team hosting the second leg.
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.
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.

Bracket

The bracket starting from the round of 16 was determined as follows:

Round	Matchups
Round of 16	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	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	Match F1: Winner S1 vs. Winner S4 Match F2: Winner S2 vs. Winner S3
Finals	Winner F1 vs. Winner F2

The bracket was decided based on the second stage draw, which was held on 4 June 2018.

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.

Match A

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''Tied 0–0 on aggregate, Santa Fe won on penalties and advanced to the quarterfinals.''

Match B

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''Tied 3–3 on aggregate, Bahia won on penalties and advanced to the quarterfinals.''

Match C

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''Tied 3–3 on aggregate, Nacional won on away goals and advanced to the quarterfinals.''

Match D

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''Junior won 2–1 on aggregate and advanced to the quarterfinals.''

Match E

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''Defensa y Justicia won 2–0 on aggregate and advanced to the quarterfinals.''

Match F

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''Fluminense won 4–0 on aggregate and advanced to the quarterfinals.''

Match G

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''Atlético Paranaense won 4–1 on aggregate and advanced to the quarterfinals.''

Match H

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''Tied 1–1 on aggregate, Deportivo Cali won on penalties and advanced to the quarterfinals.''

Quarterfinals

The first legs were played on 23–25 October, and the second legs were played on 30–31 October and 1 November 2018.

Match S1

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''Santa Fe won 3–2 on aggregate and advanced to the semifinals.''

Match S2

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''Tied 1–1 on aggregate, Atlético Paranaense won on penalties and advanced to the semifinals.''

Match S3

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''Fluminense won 2–1 on aggregate and advanced to the semifinals.''

Match S4

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''Tied 3–3 on aggregate, Junior won on away goals and advanced to the semifinals.''

Semifinals

The first legs were played on 7–8 November, and the second legs were played on 28–29 November 2018.

Match F1

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''Junior won 3–0 on aggregate and advanced to the [|finals].''

Match F2

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''Atlético Paranaense won 4–0 on aggregate and advanced to the finals.''

Finals

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.
The first leg was played on 5 December, and the second leg was played on 12 December 2018.

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Tied 2–2 on aggregate, Atlético Paranaense won on penalties.