Angola were forced to settle for a draw with Mauritania in the Africa Cup of Nations after Geraldo’s 90th-minute goal was disallowed.
Geraldo thought he had won the game in the final moments as he fired home a deep cross only for it to be rightly ruled out for offside.
Angola’s Wilson Eduardo had earlier spurned a fine chance when he put Gelson’s cross wide from close range.
Tunisia drew 1-1 with Mali on Friday in Group E’s other game.
Angola now need to beat Group E leaders Mali in their final group game on Tuesday (20:00 BST) to qualify for the last 16, while Mauritania end their group campaign against Tunisia the same day.
Angola should have come into the game high on confidence following an impressive 1-1 draw with Tunisia in their Afcon opener but they struggled to break down a resolute Mauritania side.
Eduardo really should have opened the scoring when he latched onto Gelson’s cross early in the second half and he could have netted late on, too, heading over the bar from close range before Geraldo’s winner was ruled out.
However, tournament debutants Mauritania, who earned their first Afcon point with this draw, more than matched Angola for large periods and improved as the game went on.
They twice went close through Adama Ba and Ismael Diakite but Angola defended ably on both occasions.
BBC Arabic’s Mohamed Qoutb:
Mauritania went into just their second ever AFCON match with a more cautious approach than their opener against Mali, while Angola were similarly patient.
Because of that, we’ve now had our first goalless draw at the tournament and it keeps both teams alive in the competition. But they’ll both have to raise their game against Mali or Tunisia respectively if they are to qualify for the knockout stages.