An Oran double-header on Friday in the African Nations Championship (Chan) failed to deliver a goal, leading to the elimination of Congo Brazzaville while Angola face a similar fate.
Angola drew 0-0 with Mauritania in the first match at a chilly Stade Miloud Hadefi in the western Algerian city, and the scoreline was the same between Congo and Niger.
Congo had to beat Niger in Group E to keep alive hopes of qualifying for the quarterfinals, and thought they had taken the lead on 78 minutes only to have a goal disallowed for offside.
Teenager Deo Bassinga cut in from the touchline and beat goalkeeper Mahamadou Djibo with a shot into the corner of the net, but a VAR review ruled it out.
Earlier in the second half, Imarana Seyni headed wide when well placed to put Niger ahead and a deflected Prince Ilendo shot rebounded off the woodwork to deny Congo.
Cameroon top the group with three points and Niger, who they face in the final round on Tuesday, and Congo have one each. Only the section winners advance to the knockout phase.
Mauritania had more cause for celebration than Angola as they ended a run of six straight losses since their Chan debut nine years ago.
Their destiny is in their own hands as a win over Mali in Group D on Tuesday will secure a last-eight place in a competition confined to footballers playing for clubs in their country of birth.
Angola have two points and Mali and Mauritania one each, but the southern African country will be eliminated unless their two rivals draw 0-0.
Should that result occur, Angola and Mali will be level on points, goal difference and goals scored and lots will be drawn to decide who survives.
Angola winger and man-of-the-match award winner Deivi 'Gilberto' Vieira could not hide his disappointment after the cagey stalemate.
"We came to Algeria with big dreams and our immediate goal was making the quarterfinals, but Mauritania were very good and we could not break them down," he said.
On Saturday, already qualified Algeria play Mozambique and Ethiopia meet Libya in the final Group A matches.