Four-time champions TP Mazembe of the Democratic Republic of Congo, twice runners-up El-Hilal of Sudan and rookies Moghreb Tetouan of Morocco are involved in the fight for survival.
The trio have identical records of two victories, two draws and one defeat so head-to-head records are needed to separate them with Tetouan first, Hilal second and Mazembe third.
Hilal, hoping to join fellow Omdurman outfit Al-Merrikh in the semi-fjnals, are away to out-of-contention Smouha of Egypt, who have lost four consecutive matches after opening with a dramatic triumph.
Amid numerous permutations, the one certainty is that wins for Tetouan, Hilal or Mazembe will seal progress to the penultimate stage of the marquee African Football Confederation (CAF) club competition.
Although the Congolese Ravens boast a home record of 17 wins and six draws in Champions League group maches, they have not impressed in Lubumbashi this season.
After only drawing 0-0 with Hilal, a team handled by France-born former Mali coach Patrice Carteron scraped a 1-0 win over Smouha thanks to a goal from Ivorian Roger Assale.
Tetouan, who lost six-goal leading 2015 Champions League scorer Mouhcine Iajour to a Qatari club after the qualifying stage, have experienced mixed fortunes on the road.
They surrendered a two-goal lead to lose at Smouha before shocking Hilal in Omdurman with the lone goal coming from a penalty converted by Ahmed Jahouh.
Mazembe dominated the first half and Tetouan the second when the clubs fought a goalless draw in Morocco two months ago.
Hilal, beaten finalists twice pre-1997 when it was an exclusively knockout competition and called the CAF Champions Cup, have drawn away to Mazembe and Tetouan.
That should bolster the confidence of a side coached by Tunisian Nabil Kouki as they prepare to confront Smouha in ancient Mediterranean city Alexandria.
Mudather al-Tayeb, Hamid Nizar and Burkina Faso-born Boubacar Kebe have scored three Champions League goals each for Hilal this season.
Cameroonian goalkeeper Maxime Feudjou and a defence marshalled by Saif Masawi have conceded only two goals in 450 minutes of group play.
While tension mounts ahead of the Group A finale, Group B has been settled with USM Alger of Algeria certain to finish first and Merrikh second whatever the outcome of their Friday clash in Omdurman.
Reigning champions Entente Setif, who managed just one win and three goals from five games, have been eliminated and only pride will be at stake when they host Mouloudia El Eulma in an Algerian derby.
12.09.2015 15H30 TP Mazembe (DR Congo) vs Moghreb Tetouan (Morocco)
12.09.2015 15H30 Smouha (Egypt) vs El Hilal (Sudan)
11.09.2015 20H30 El Merreikh (Sudan) vs USM Alger (Algeria)
11.09.2015 20H30 ES Setif (Algeria) vs MC Eulma (Algeria)