The winners and runners-up of each of the eight groups in the group stage qualified for the knockout stage. Both West Zone and East Zone had eight teams qualified.
In the round of 16, the winners of one group played the runners-up of another group in the same zone, with the group winners hosting the second leg. The matchups are determined as follows: ;West Zone
Winner Group A vs. Runner-up Group C
Winner Group C vs. Runner-up Group A
Winner Group B vs. Runner-up Group D
Winner Group D vs. Runner-up Group B
;East Zone
Winner Group E vs. Runner-up Group G
Winner Group G vs. Runner-up Group E
Winner Group F vs. Runner-up Group H
Winner Group H vs. Runner-up Group F
The draw for the quarter-finals was held on 18 June 2015, 16:00, at the Grand Millennium Hotel in Kuala Lumpur, Malaysia. Teams from different zones could not be drawn into the same tie, and there was no seeding or country protection, so teams from the same association could be drawn into the same tie. In the semi-finals, the matchups were determined by the quarter-final draw: Winner QF1 vs. Winner QF2 and Winner QF3 vs. Winner QF4, with winners QF2 and QF4 hosting the second leg. In the final, the finalist from the West Zone hosted the first leg, while the finalist from the East Zone hosted the second leg.
Round of 16
!colspan=5|West Zone !colspan=5|East Zone
First leg
---- ---- ---- ---- ---- ---- ----
Second leg
4–4 on aggregate. Kashiwa Reysol won on away goals. ---- Jeonbuk Hyundai Motors won 2–1 on aggregate. ---- Lekhwiya won 4–3 on aggregate. ---- Al-Hilal won 3–1 on aggregate. ---- Gamba Osaka won 6–3 on aggregate. ---- Guangzhou Evergrande won 3–2 on aggregate. ---- 3–3 on aggregate. Al-Ahli won on away goals. ---- 2–2 on aggregate. Naft Tehran won on away goals.
Quarter-finals
!colspan=5|West Zone !colspan=5|East Zone
First leg
---- ---- ---- ;Notes
Second leg
Guangzhou Evergrande won 4–2 on aggregate. ---- Al-Hilal won 6–3 on aggregate. ---- Gamba Osaka won 3–2 on aggregate. ---- Al-Ahli won 3–1 on aggregate.
Semi-finals
!colspan=5|West Zone !colspan=5|East Zone
First leg
----
Second leg
Al-Ahli won 4–3 on aggregate. ---- Guangzhou Evergrande won 2–1 on aggregate.