Tunisia's CS Sfaxien and Renaissance Berkane of Morocco became the first teams to qualify for this season's African Confederation Cup quarter-finals.
Both secured home victories in their penultimate group games on Sunday to advance.
13 clubs remain in contention for the other six quarter-final places with holders Raja Casablanca still harbouring faint hopes of progressing despite being held to another draw.
Only the top two from each group qualify for the last-eight of Africa's second tier football tournament.
Group A
Renaissance Berkane never looked troubled against Congo Brazzaville visitors AS Otoho Oyo in Berkane as they booked their place in the last eight.
Togo's Kodjo Fo-Doh Laba scored after only six minutes to set up a 3-0 triumph. It was his fifth goal of the campaign and Salman el Haj and Abdessamad el Mobaraky scored their first as Berkane outclassed Otoho.
Berkane also reached the Confederation Cup quarter-finals last season and have dominated Group A - which includes three Moroccan sides.
Raja Casablanca's hopes of progressing hang by a thread after being held 0-0 at home by Hassania Agadir in Rabat, leaving the holders without a victory in this group phase.
Ohoyo's defeat means Raja's faint hopes of progressing remain alive going into the final round of group games.
Berkane have 11 points, Otoho and Hassania five each with the Congolese second on head-to-head records, and Raja four.
Group B
CS Sfaxien defeated fellow Tunisians Etoile du Sahel 2-1 in Sfax to advance, with Nassim Hnid converting a 77th-minute penalty to secure maximum points for the hosts.
Firas Chaouat of Sfaxien had broken the deadlock on 58 minutes and Etoile reacted swiftly, equalising within four minutes through Saddam Ben Aziza.
After regaining the lead, Sfaxien had to play the final seven minutes with 10 men after Mohamed Ali Moncer was sent off.
Despite losing, Etoile are also likely to reach the knockout phase as closest rivals Enugu Rangers of Nigeria drew 1-1 away to Burkina Faso academy club Salitas FC in Ouagadougou.
Enugu overcame the sending off of Semiu Liadi on 29 minutes to take a first-half lead through George Ifeanyi, but Iliasse Sawadogo levelled with the first Salitas goal in five group games.
Sfaxien have nine points from five matches, twice Confederation Cup winners Etoile seven, Enugu five and Salitas four.
Group C
Nkana's joy at hammering fellow Zambians Zesco United 3-0 in Group C was heightened when Asante Kotoko of Ghana and Al Hilal of Sudan drew 1-1 later in Kumasi.
The Ghana stalemate kept Nkana in top spot on nine points, Hilal have eight, former African champions Kotoko seven and Zesco four.
Although Nkana conclude their schedule with a tricky trip to Hilal, the Kitwe club will qualify with any result - as long as Kotoko do not win at Zesco.
Nkana went ahead against Zesco United on 64 minutes through Kelvin Kampamba.
Late goals from Ronald Kampamba and Shadrick Musonda sealed a victory that propelled them to the top of Group C.
Group D
Zamalek of Egypt trounced Gor Mahia of Kenya 4-0 at home to rise from last to first in Group D.
Centre-back Mahmoud Alaa came forward to powerfully nod a free-kick into the net on 12 minutes and Youssef 'Obama' Ibrahim doubled the lead midway through the opening half.
Late goals from Tunisian Ferjani Sassi, after dribbling past several defenders and rounding goalkeeper Fredrick Odhiambo, and Omar el Said completed the rout.
Zamalek top the table with eight points, Petro Atletico of Angola and NA Hussein Dey of Algeria have seven each and Gor six.
Meanwhile, Petro Atletico of Angola moved from the bottom to the top of Group D thanks to a 2-0 home victory against previous pacesetters NA Hussein Dey of Algeria.
Ricardo 'Job' Estevao scored after 16 minutes and Brazilian Tiago Azulao doubled the lead six minutes before half-time in Luanda by converting a penalty.
It was the fifth goal for Sao Paulo-born Azulao in the competition this season.
Petro and Hussein Dey have seven points each with the better head-to-head record of the Angolans placing them first.
Source: BBC