InterClube became Angola's first Confederation Cup semi-finalists after beating Nigerian visitors Kaduna United 4-1 at home on Sunday.
Capuco (2), Pingo and Manucho Barros scored to ensure that the Luanda side finishes in the top two in Group A.
Tunisia's Club Africain stay in second place in the group thanks to a 1-0 over visiting Asec Mimosas of Ivory Coast.
The game however was overshadowed by violent clashes between fans and police.
The problems lead to the officials stopping the game after 20 minutes as police restored order and emptied the stadium of the majority of supporters.
When the game did resume it was Aymen Soltani who scored the winning goal in the 58th minute.
Club Africain now travel to face Kaduna United next Sunday to decide who will join InterClube in the last four.
The Tunisians know that a draw will take them through while the Nigerian club must win to claim second spot thanks to a better head-to-head record.
Reaching the penultimate stage compensates InterClube for two disastrous previous appearances in the group phase of the Confederation Cup.
Like Asec and Africain, InterClube began 2011 in the African Champions League only to trip up at the final qualifying hurdle and drop down to the Confederation Cup.
In Group B, MAS are on the verge of reaching the semi-finals after a 1-0 away victory against struggling Algerian outfit JS Kabylie late on Saturday.
Hamza Abourazzouk raised his goal tally this season in the compeetition to four with the winner after 55 minutes, before a packed 80,000-capacity 5 July stadium in Algiers.
MAS are hoping to become the third Moroccan winners of an event that replaced the Cup Winners Cup and CAF Cup in 2004 and the second in a row after FUS Rabat's surprise success last season.
Elsewhere, DC Motema Pembe of DR Congo drew 0-0 at home to Sunshine Stars of Nigeria on Sunday in a clash of the sides chasing second spot in the group.
Their chances of reaching the semi-finals will depend on how they fare in their final group matches on 16-18 September.
Courtesy of a better head-to-head record than Motema Pembe, who travel to MAS, Sunshine Stars will qualify with a win at home to JS Kabylie.