Angolan champions Primeiro Agosto edged Mbabane Swallows 2-1 at home on Tuesday to book a place into the last eight.
DR Congo forward Jacques Bitumba and Geraldo scored in the first half, before Quadri Aladeokun pulled a goal back for visitors Swallows who needed a win to enhance their quarter-final chances.
Victory for Agosto saw them maintaining second place in the group with nine points to join Etoile du Sahel who qualified for the last eight with one match to go.
Swallows had arrived in Luanda with hopes of progressing to the kockout phase had they won.
With Zesco United being held to a 1-1 draw by Etoile in Ndola, Swallows blew away a big opportunity to play in the quarter-finals.
Having beaten Agosto 1-0 in the reverse fixture, Swallows fancied their chances in this game but Bitumba struck on 34 minutes before Nigerian forward Akinfenwa Ibukun fed Geraldo to double Agosto’s advantage four minutes later.
But Swallows tried to come back with Njabulo Ndlovu setting up Aladeokun eight minutes after the restart.
It was Agosto’s resilience that saw them hold on to the slim victory which crucially sailed them into the quarter-finals.
Elsewhere in Ndola, Lazarous Kambole continued with his fine form with a goal but it was in vain as Etoile held Zesco United to a 1-1 draw.
Victory for Zesco would have not been enough to guarantee them a last eight berth as they had to pray for Agosto to lose also.
Kambole struck as early as eight minutes into the match for his fourth goal in two games but Etoile hit back with 20 minutes to go.
Etoile defender Rami Bedoui equalised for the Tunisians who were under no pressure in this game.