# 2021 AFC Cup knockout stage

The 2021 AFC Cup knockout stage was played from 25 August to 5 November 2021. A total of 8 teams competed in the knockout stage to decide the champions of the 2021 AFC Cup. Teams from ASEAN Zone did not compete in the knockout stage, due to the cancellation of group stage matches in ASEAN Zone.

## Qualified teams

The following teams advanced from the group stage:
* The winners of each of the three groups and the best runners-up in the West Asia Zone (Groups A–C) advanced to the Zonal semi-finals.
* The winners of each group in the South Asia Zone (Group D), and the East Asia Zone (Group J) advanced to the Inter-zone play-off semi-finals.
* The winners of each group in the Central Asia Zone (Groups E–F) advanced to the Zonal finals.
* Key to colours
* Teams which enter the Inter-zone play-off finals
* Teams which enter the Inter-zone play-off semi-finals
* Teams which enter the Zonal finals
* Teams which enter the Zonal semi-finals
| Zone | Group | Winners | Best runners-up |
| West Asia Zone | A | Al-Ahed | Al-Salt (Group B) |
| West Asia Zone | B | Al-Muharraq | Al-Salt (Group B) |
| West Asia Zone | C | Al-Kuwait | Al-Salt (Group B) |
| South Asia Zone | D | Mohun Bagan SG | — |
| Central Asia Zone | E | Ahal | — |
| Central Asia Zone | F | Nasaf | — |
| East Asia Zone | J | Lee Man | — |

## Format

In the knockout stage, the eight teams played a single-elimination tournament. Each tie was played as a single match. Extra time and penalty shoot-out were used to decide the winners if necessary (Regulations Article 9.3 and 10.1).

## Schedule

The schedule of each round is as follows (W: West Asia Zone; C: Central Asia Zone). Matches in the West Asia Zone will be played on Mondays and Tuesdays, while matches in the Central Zone and the Inter-zone play-offs will be played on Tuesdays and Wednesdays.
| Round | Date |
| Zonal semi-finals | 20–21 September 2021 (W) |
| Zonal finals | 25 August 2021 (C), 20 October 2021 (W) |
| Inter-zone play-off semi-finals | 21–22 September 2021 |
| Inter-zone play-off final | 20 October 2021 |
| Final | 5 November 2021 |

## Bracket

The bracket of the knockout stage was determined as follows:
| Round | Matchups |
| Zonal semi-finals | (Matchups and order of legs determined by identity of best runners-up: In West Asia Zone, the first team listed host first leg, and the second team listed host second leg. In ASEAN Zone, the first team listed host the match) West Asia Zone If best runners-up from Group A WSF1: Group C winners vs. Group A winners WSF2: Group A runners-up vs. Group B winners If best runners-up from Group B WSF1: Group A winners vs. Group B winners WSF2: Group B runners-up vs. Group C winners If best runners-up from Group C WSF1: Group B winners vs. Group C winners WSF2: Group C runners-up vs. Group A winners ASEAN Zone If best runners-up from Group G ASF1: Group G winners vs. Group I winners ASF2: Group H winners vs. Group G runners-up If best runners-up from Group H ASF1: Group H winners vs. Group G winners ASF2: Group I winners vs. Group H runners-up If best runners-up from Group I ASF1: Group I winners vs. Group H winners ASF2: Group G winners vs. Group I runners-up |
| Zonal finals | (Order of legs decided by draw) West Asia Zone WF: Winners of WSF1 vs. Winners of WSF2 Central Asia Zone CF: Group E winners vs. Group F winners ASEAN Zone AF: Winners of ASF1 vs. Winners of ASF2 |
| Inter-zone play-off semi-finals | (Matchups and order of legs decided by draw, involving winners of Group D, Group J, CF, and AF) IZSF1 IZSF2 |
| Inter-zone play-off finals | (Winners of IZSF1 host first leg, Winners of IZSF2 host second leg) IZF: Winners of IZSF1 vs. Winners of IZSF2 |
| Final | (Winners of WF host the match, as alternated from previous season's final) Winners of WF vs. Winners of IZF |
| Zonal semi-finals | Zonal semi-finals | Zonal semi-finals | Zonal finals | Zonal finals | Zonal finals | Inter-zone play-off semi-finals | Inter-zone play-off semi-finals | Inter-zone play-off semi-finals | Inter-zone play-off final | Inter-zone play-off final | Inter-zone play-off final | Final | Final | Final |
| Al-Muharraq | Al-Muharraq | 3 | | | | | | | | | | |
| Al-Ahed | Al-Ahed | 0 | | | | | | | | | | |
| Al-Ahed | Al-Ahed | 0 | Al-Muharraq | Al-Muharraq | 2 | | | | | | | | | |
| Al-Kuwait | Al-Kuwait | 2 | Al-Kuwait | Al-Kuwait | 0 | | | | | | | |
| Al-Salt | Al-Salt | 0 | | | | | | | | | | | | |
| | | | | | | | | | | | | Al-Muharraq | Al-Muharraq | 3 |
| | | | Nasaf | Nasaf | 3 | | | | | | | Nasaf | Nasaf | 0 |
| | | | Ahal | Ahal | 2 | Nasaf | Nasaf | 6 | | | | | | |
| | | | | | | Mohun Bagan SG | Mohun Bagan SG | 0 | Nasaf (a.e.t.) | Nasaf (a.e.t.) | 3 | | | |
| | | | | | | | | | Lee Man | Lee Man | 2 | | | |

## Zonal semi-finals
### Summary

The West Asia Zonal semi-finals were played over one leg, with the home team determined by the draw mechanism based on which group runners-up qualify. A group winner hosted the match against a group runner-up. If two group winners played each other, one of the group winner (whose group runner-up qualify) hosted the match.
West Asia Zone :
| Team 1 | Score | Team 2 |
ASEAN Zone :
| Team 1 | Score | Team 2 |

### West Asia Zone
## Zonal finals
### Summary

The West Asia and Central Asia Zonal final were played over one leg, with the home team decided by draw. The winners of the West Asia Zonal final advanced to the final, while the winners of the Central Asia Zonal final advanced to the Inter-zone play-off semi-finals.
West Asia Zone :
| Team 1 | Score | Team 2 |
Central Asia Zone :
| Team 1 | Score | Team 2 |
ASEAN Zone :
| Team 1 | Score | Team 2 |

### Central Asia Zone
## Inter-zone play-off semi-finals
### Summary

After matches in ASEAN Zone was cancelled, there were only three teams which qualified to the Inter-zone play-off semi-finals, i.e., the winners of the South Asia Zone (Group D), the winners of the East Asia Zone (Group J), and the winners of the Central Zonal final. The three Zonal champions were drawn into two pairings where one club got a bye to the Inter-zone play-off final, which happened for Lee Man. The matchups and order of legs decided by draw, without any seeding with the winner of Central Zonal Final hosting the match and the winner of South Asia Zone being the away team.
| Team 1 | Score | Team 2 |
| Nasaf | 6–0 | Mohun Bagan SG |

### Matches
## Inter-zone play-off final
### Summary

In the Inter-zone play-off final, the two teams which advanced from the Inter-zone play-off semi-finals played each other, with the order of legs determined by the Inter-zone play-off semi-final draw. The winners of the Inter-zone play-off final advanced to the final.
| Team 1 | Score | Team 2 |
| Nasaf | 3–2 (a.e.t.) | Lee Man |

### Matches
## Final

The final was played over one leg, between the winners of the West Asia Zonal final and the winners of the Inter-zone play-off final. The home team was determined on a rotation basis, with the match hosted by the winners of the West Asia Zonal final, as in the case of odd-numbered years (Regulations 9.1.2).