Title-holders Wydad Casablanca of Morocco and Al Ahly of Egypt ground out 1-0 victories Friday to reach the CAF Champions League quarter-finals.
A sizzling Anas el Asbahi shot on 56 minutes earned Wydad maximum points against Mamelodi Sundowns of South Africa in a cagey Casablanca clash of few scoring opportunities.
Walid Azaro struck after 32 minutes as Ahly made it three away Champions League victories in a row over Esperance of Tunisia in Rades.
Elsewhere, Horoya of Guinea beat Port of Togo 2-1 in Conakry and TP Mazembe of the Democratic Republic of Congo fought back to force a 1-1 draw at Entente Setif of Algeria.
Wydad, who beat Ahly 2-1 on aggregate in the 2017 final, also clinched first place in Group C, which means they will face a group runner-up away and at home in the quarter-finals.
The defending champions barely tested Sundowns' Ugandan goalkeeper Denis Onyango until El Asbahi unleashed a thunderbolt from outside the box that flew into the corner of the net.
Sundowns were equally ineffective in attack until the closing stages when they forced a number of corners and Venezuelan Jose Ali Meza wasted a good chance by shooting weakly.
The South African side must now defeat second-place Horoya in Pretoria on August 28 to finish runners-up on the head-to-head rule having drawn 2-2 in Conakry during May.
Mandela Ocansey gave the Guinean outfit an early lead over Port, Ablamvi Djadja levelled soon after half-time and Bolaji Sakin netted the 58th-minute winner.
Ahly continued their Champions League dominance of Esperance in Tunisia thanks to Moroccan Azaro, whose goal continued a turnaround under recently hired coach Patrice Carteron.
When the Frenchman took charge, the 'Cairo Red Devils' were bottom of Group A with just one point following a shock loss in Uganda against Kampala Capital City Authority.
But back-to-back victories over Township Rollers of Botswana and the triumph at already-qualified Esperance have lifted Ahly to the top of the table.
If Ahly beat Kampala in Egypt this month, they are guaranteed to win the group while seeking a record-extending ninth Champions League (formerly African Cup of Champions Clubs) title.
A second successive away match in Algeria brought another draw for five-time champions Mazembe, who appear the strongest title contenders this season from outside north Africa.
Mohamed Islam Bakir put twice African title-holders Setif ahead just before the hour and Zambian Kabaso Chongo equalised 14 minutes from time.
Mazembe are sure to win Group B and 1976 African champions Mouloudia Alger are likely to join them in the September 3 quarter-finals draw.
Mouloudia, away to winless Difaa el Jadida of Morocco, are among eight clubs who will be in action Saturday.