Nigerian midfielder Okonkwo found the net in the 29th minute against his former side, who just needed a draw to advance.

His curly shot from the left side of the area hit the post and settled into the back of the net as Pirates leapfrogged two-time African champions Enyimba to second spot of Group B.

Pirates finished their group stage campaign with nine points, one ahead of Enyimba and three behind leaders ASEC Mimosas.

They wait to know their opponents in the two-legged semis. Pirates will play Group A winners, who will be either title holders Ahli or Tunisia's Sfaxien.

Ahli, in charge of the group on 10 points and already guaranteed a last-four berth, play Algerian side JS Kabylie away on Sunday while second-place Sfaxien host Ghana's Asante Kotoko.