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.
The 16 winners of the second stage advanced to the round of 16.
<section begin=Seeding /> Starting from the round of 16, the teams were seeded according to the second stage draw, with each team assigned a "seed" 1âÂÂ16 corresponding to the tie they win (O1âÂÂO16) (Regulations Article 22.c).<section end=Seeding />
<section begin=Format /> Starting from the round of 16, the teams played a single-elimination tournament with the following rules:
The bracket starting from the round of 16 was determined as follows:
<section begin=Bracket /> The bracket was decided based on the second stage draw, which was held on 4 June 2018. <section end=Bracket />
The first legs were played on 21âÂÂ22 August, 18âÂÂ20 and 26 September, and the second legs were played on 19, 25, 27 September, and 2âÂÂ4 October 2018. <section begin=Round of 16 />
<section end=Round of 16 />
Tied 0âÂÂ0 on aggregate, Santa Fe won on penalties and advanced to the quarterfinals (Match S1).
Tied 3âÂÂ3 on aggregate, Bahia won on penalties and advanced to the quarterfinals (Match S2).
Tied 3âÂÂ3 on aggregate, Nacional won on away goals and advanced to the quarterfinals (Match S3).
Junior won 2âÂÂ1 on aggregate and advanced to the quarterfinals (Match S4).
Defensa y Justicia won 2âÂÂ0 on aggregate and advanced to the quarterfinals (Match S4).
Fluminense won 4âÂÂ0 on aggregate and advanced to the quarterfinals (Match S3).
Atlético Paranaense won 4âÂÂ1 on aggregate and advanced to the quarterfinals (Match S2).
Tied 1âÂÂ1 on aggregate, Deportivo Cali won on penalties and advanced to the quarterfinals (Match S1).
The first legs were played on 23âÂÂ25 October, and the second legs were played on 30âÂÂ31 October and 1 November 2018. <section begin=Quarterfinals />
<section end=Quarterfinals />
Santa Fe won 3âÂÂ2 on aggregate and advanced to the semifinals (Match F1).
Tied 1âÂÂ1 on aggregate, Atlético Paranaense won on penalties and advanced to the semifinals (Match F2).
Fluminense won 2âÂÂ1 on aggregate and advanced to the semifinals (Match F2).
Tied 3âÂÂ3 on aggregate, Junior won on away goals and advanced to the semifinals (Match F1).
The first legs were played on 7âÂÂ8 November, and the second legs were played on 28âÂÂ29 November 2018. <section begin=Semifinals />
<section end=Semifinals />
Junior won 3âÂÂ0 on aggregate and advanced to the finals.
Atlético Paranaense won 4âÂÂ0 on aggregate and advanced to the 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 (Regulations Article 28).
The first leg was played on 5 December, and the second leg was played on 12 December 2018. <section begin=Finals />
Tied 2âÂÂ2 on aggregate, Atlético Paranaense won on penalties.<section end=Finals />