Guardianes 2021 Liga MX final phase

The Torneo Guardianes 2021 (stylized as Guard1anes) Liga MX final phase was played between 8 May 2021 to 30 May 2021. A total of 12 teams competed in the final phase to decide the champions of the Guardianes 2021 Liga MX season. For the second straight season, an additional qualifying round, the reclassification or repechaje, was employed, which expanded the number of playoff spots to 12.

Both finalists qualified to the 2022 CONCACAF Champions League.

Qualified teams
The following teams qualified for the championship stage.

In the following tables, the number of appearances, last appearance, and previous best result count only those in the short tournament era starting from Invierno 1996 (not counting those in the long tournament era from 1943–44 to 1995–96).

Reclassification

 * All rounds will be played in a single-leg hosted by the higher seed
 * If a game ends in a draw, it will proceed directly to a penalty shoot-out.

Liguilla

 * Teams are re-seeded after each round.
 * The winners of the Reclassification matches are seeded based on their ranking in the classification table.
 * Team with more goals on aggregate after two matches advance.
 * Away goals rule is applied in the quarter-finals and semi-finals, but not the final.
 * In the quarter-finals and semi-finals, if the two teams are tied on aggregate and away goals, the higher seeded team advances.
 * In the final, if the two teams are tied after both legs, the match will go to extra time and, if necessary, a shoot-out.
 * Both finalists will qualify to the 2022 CONCACAF Champions League.

Summary
Matches took place on 8–9 May 2021. 


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Seeding
The following was the final seeding for the final phase. The winners of the Reclassification matches were seeded based on their position in the classification table.

Bracket




Summary
The first legs were played on 12–13 May, and the second legs were played on 15–16 May. 


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Second leg
''1–1 on aggregate and tied on away goals. Puebla advanced due to being the higher seed in the classification table.''

Cruz Azul won 4–3 on aggregate.

Santos Laguna won 3–2 on aggregate.

''5–5 on aggregate. Pachuca won on away goals.''

Summary
The first legs will be played on 19–20 May, and the second legs will be played on 22–23 May. 


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Second leg
Cruz Azul won 1–0 on aggregate.

Santos Laguna won 3–1 on aggregate.

Summary
The first leg was played on 27 May, and the second leg was played on 30 May. 


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Second leg
Cruz Azul won 2–1 on aggregate.