Defending champions Enyimba of Nigeria must avoid defeat away to Ahly of Egypt this weekend if they are to seal an African Champions League semi-finals place.
Ahly have 11 points and an unassailable lead in Group A entering the final series of pool games, leaving Enyimba, on seven points, and Morocco's Raja Casablanca to fight for second spot.
Raja, who have five points, have a less intimidating assignment away to winless Ajax Cape Town of South Africa.
Victory for Raja will lift them to eight points, but one point will suffice for Enyimba because of their superior head-to-head record.
Ahly may have secured passage to the penultimate phase of a competition carrying a one-million-dollar first prize and an invitation to December's inaugural Fifa Club World Championship in Japan, but there is a lot at stake for them.
The 'Red Devils' of Cairo boast a 40-match unbeaten record in competitive matches and Portuguese coach Manuel Jose says his players are thriving on the challenge.
Ahly hold a psychological edge over Enyimba having won in Nigeria two months ago courtesy of an early goal from Emad Moteab, who has scored five Champions League goals this year.
Only Enyimba's eight-goal Joetex Frimpong has been deadlier this year, but the Ghanaian could miss the Cairo clash after being carried off in last weekend's World Cup qualifier against Uganda.
Leaders Zamalek of Egypt and Etoile Sahel of Tunisia have collected the Group B tickets to the semi-finals, and their showdown in the Mediterranean town of Sousse will decide who ends first and avoids Ahly in the next round.
Zamalek have a two-point advantage so a draw will suffice and the 'White Knights' of Cairo can draw confidence from a come-from-behind 2-1 away win over Esperance, the other Tunisian competitors.
Esperance complete their schedule away to Ivorian outfit Asec, a young, skilful side who deserve better than bottom place, and victory in Abidjan will lift them above the legendary Tunis-based 'Blood and Golds'.
Asec will be without 30-year-old striker Alhassane Koivogui, who joined opponents Etoile this week and so will miss the game.
"It is a big move for me at this stage of my career," the Guinean said recently.
"Etoile told me they liked my fighting spirit, but I will miss the ASEC fans, they have been great to me."