2018 AFC Cup knockout stage

The 2018 AFC Cup knockout stage was played from 7 May to 27 October 2018. A total of 11 teams competed in the knockout stage to decide the champions of the 2018 AFC Cup.

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) and the ASEAN Zone (Groups F–H) advanced to the Zonal semi-finals.
• The winners of each group in the Central Asia Zone (Group D), the South Asia Zone (Group E), and the East Asia Zone (Group I) advanced to the Inter-zone play-off semi-finals.

In the knockout stage, the 11 teams played a single-elimination tournament. Each tie was played on a home-and-away two-legged basis, except the final which was played as a single match. The away goals rule (for two-legged ties), extra time (away goals do not apply in extra time) and penalty shoot-out were used to decide the winner if necessary (Regulations Article 11.3).

The schedule of each round was as follows (W: West Asia Zone; A: ASEAN Zone). Matches in the West Asia Zone were played on Mondays and Tuesdays, while matches in the ASEAN Zone and the Inter-zone play-offs were played on Tuesdays and Wednesdays.

The bracket of the knockout stage was determined as follows:

West Asia Zone If best runners-up from Group A WSF1: Winner Group A vs. Winner Group C WSF2: Runner-up Group A vs. Winner Group B If best runners-up from Group B WSF1: Winner Group B vs. Winner Group A WSF2: Runner-up Group B vs. Winner Group C If best runners-up from Group C WSF1: Winner Group C vs. Winner Group B WSF2: Runner-up Group C vs. Winner Group A

ASEAN Zone If best runners-up from Group F ASF1: Winner Group F vs. Winner Group H ASF2: Runner-up Group F vs. Winner Group G If best runners-up from Group G ASF1: Winner Group G vs. Winner Group F ASF2: Runner-up Group G vs. Winner Group H If best runners-up from Group H ASF1: Winner Group H vs. Winner Group G ASF2: Runner-up Group H vs. Winner Group F | West Asia Zone If best runners-up from Group A WSF1: Winner Group A vs. Winner Group C WSF2: Runner-up Group A vs. Winner Group B If best runners-up from Group B WSF1: Winner Group B vs. Winner Group A WSF2: Runner-up Group B vs. Winner Group C If best runners-up from Group C WSF1: Winner Group C vs. Winner Group B WSF2: Runner-up Group C vs. Winner Group A | ASEAN Zone If best runners-up from Group F ASF1: Winner Group F vs. Winner Group H ASF2: Runner-up Group F vs. Winner Group G If best runners-up from Group G ASF1: Winner Group G vs. Winner Group F ASF2: Runner-up Group G vs. Winner Group H If best runners-up from Group H ASF1: Winner Group H vs. Winner Group G ASF2: Runner-up Group H vs. Winner Group F | | West Asia Zone If best runners-up from Group A WSF1: Winner Group A vs. Winner Group C WSF2: Runner-up Group A vs. Winner Group B If best runners-up from Group B WSF1: Winner Group B vs. Winner Group A WSF2: Runner-up Group B vs. Winner Group C If best runners-up from Group C WSF1: Winner Group C vs. Winner Group B WSF2: Runner-up Group C vs. Winner Group A | ASEAN Zone If best runners-up from Group F ASF1: Winner Group F vs. Winner Group H ASF2: Runner-up Group F vs. Winner Group G If best runners-up from Group G ASF1: Winner Group G vs. Winner Group F ASF2: Runner-up Group G vs. Winner Group H If best runners-up from Group H ASF1: Winner Group H vs. Winner Group G ASF2: Runner-up Group H vs. Winner Group F | | | (Order of legs decided by draw)

West Asia Zone WF: Winner WSF1 vs. Winner WSF2

ASEAN Zone AF: Winner ASF1 vs. Winner ASF2 | West Asia Zone WF: Winner WSF1 vs. Winner WSF2 | ASEAN Zone AF: Winner ASF1 vs. Winner ASF2 | | West Asia Zone WF: Winner WSF1 vs. Winner WSF2 | ASEAN Zone AF: Winner ASF1 vs. Winner ASF2 | | | (Matchups and order of legs decided by draw, involving Winner Group D, Winner Group E, Winner Group I, and Winner AF)

IZSF1

IZSF2 | IZSF1 | IZSF2 | | IZSF1 | IZSF2 | | | (Winner IZSF1 host first leg, Winner IZSF2 host second leg) IZF: Winner IZSF1 vs. Winner IZSF2 | | | | (Winner WF host match, as alternated from previous season's final) Winner WF vs. Winner IZF | | |

The bracket was decided after the draw for the Zonal finals and the Inter-zone play-off semi-finals, which was held on 23 May 2018, 15:00 MYT (UTC+8), at the AFC House in Kuala Lumpur, Malaysia.

In the Zonal semi-finals, the four qualified teams from the West Asia Zone (Groups A–C) played in two ties, and the four qualified teams from the ASEAN Zone (Groups F–H) played in two ties, with the matchups and order of legs determined by the group stage draw and the identity of the best runners-up.

Al-Jazeera won 2–1 on aggregate.

Al-Quwa Al-Jawiya won 5–3 on aggregate.

Home United won 6–3 on aggregate.

Ceres–Negros won 6–5 on aggregate.

The draw for the Zonal finals was held on 23 May 2018. In the Zonal finals, the two winners of West Asia Zonal semi-finals played each other, and the two winners of ASEAN Zonal semi-finals played each other, with the order of legs decided by draw. The winners of the West Asia Zonal final advanced to the final, while the winners of the ASEAN Zonal final advanced to the Inter-zone play-off semi-finals.

Al-Quwa Al-Jawiya won 4–1 on aggregate.

Home United won 3–1 on aggregate.

The draw for the Inter-zone play-off semi-finals was held on 23 May 2018. In the Inter-zone play-off semi-finals, the four zonal winners other than the West Asia Zone played in two ties, i.e., the winners of the Central Asia Zone (Group D), the winners of the South Asia Zone (Group E), the winners of the East Asia Zone (Group I), and the winners of the ASEAN Zonal final (whose identity was not known at the time of the draw), with the matchups and order of legs decided by draw, without any seeding.

April 25 won 11–1 on aggregate.

Altyn Asyr won 5–2 on aggregate.

In the Inter-zone play-off final, the two winners of 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.

3–3 on aggregate. Altyn Asyr won on away goals.

In the final, the winners of the West Asia Zonal final and the winners of the Inter-zone play-off final played each other, with the host team (winners of the West Asia Zonal final) alternated from the previous season's final.

• AFC Cup, the-AFC.com
• AFC Cup 2018, stats.the-AFC.com