[1] A total of 8 teams competed in the knockout stage to decide the champions of the 2021 AFC Cup.
Extra time and penalty shoot-out were used to decide the winners if necessary (Regulations Article 9.3 and 10.1).
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.
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 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).