Four teams qualified for the quarter-finals in the first spell of action on Wednesday. They are Umm Salal (Qatar), Pakhtakor and Bunyodkor (both Uzbekistan), and Al Ittihad (Saudi Arabia).
The remaining four Round of 16 matches will be played on 24 June.
Japan’s Nagoya Grampus host Korea Republic’s Suwon Bluewings, defending champions Gamba Osaka take on Kawasaki Frontale in an all-Japan clash, Japan’s Kashima Antlers clash with Korea Republic’s FC Seoul and Korea Republic’s Pohang Steelers meet Australia’s Newcastle Jets.
The quarter-finals and semi-finals will be home-and-away affairs while the one-off final will be played in Tokyo on 7 November.
The first leg of the quarter-finals will be played on either 23 or 24 September, while the second leg will be played on 30 September. The two-legged semi-finals have been slated for 21 and 28 October.