The unbeaten record of Algerian club CS Constantine in the CAF Champions League ended on Friday when they surprisingly fell 1-0 at home to Tunisian outfit Club Africain.
Burkina Faso-born Bassirou Compaore scored on the stroke of half-time as the visitors avenged a home defeat by the Algerians in Group C two months ago.
An Algerian side coached by Frenchman Denis Lavagne had won six and drawn two qualifying and group matches before hosting Africain.
In the same section, struggling Egyptian team Ismaily came from behind to draw 1-1 with five-time African champions TP Mazembe from the Democratic Republic of Congo.
Despite the setback for Constantine and the failure of Mazembe to secure maximum points, they remain likely to fill the top two positions and qualify for the quarter-finals.
Constantine, formed 120 years ago but competing in the elite pan-African club competition for only the second time, top the table with 10 points.
Mazembe have eight points, Club Africain seven and Ismaily two with one round remaining in the six-matchday group phase.
A possible path for Club Africain into the last eight would be to trounce Ismaily in Tunisia next Saturday and hope Constantine suffer a heavy loss against Mazembe in central Africa.
Alternatively, if Mazembe fail to win in their southern Congolese fortress of Lubumbashi, the Tunisians will progress by winning at home.
Compaore scored his first goal of the Champions League as Africain continued a comeback under French coach Victor Zvunka after a humiliating 8-0 thrashing at Mazembe last month.
Last year, Zvunka defied the odds by taking Horoya to the 2018 CAF Champions League quarter-finals, the first Guinean club to get beyond the group stage.
And just 10 days after the eight-goal humiliation, the 67-year-old former defender capped once by France improved Club Africain sufficiently to force a 0-0 draw with Mazembe in Tunis.
Ismaily, banned from the competition over missile-throwing supporters then reinstated after an appeal, fell behind on 40 minutes when Elia Meschak netted for Mazembe in Alexandria.
But Abdelrahman Magdy scored his first Champions League goal since early December to bring the clubs level 10 minutes into the second half.
The game was moved 350 kilometres (220 miles) from Suez canal city Ismailia to a military-controlled stadium in ancient Mediterranean city Alexandria to minimise the risk of crowd trouble.