Equatorial Guinea stunned Algeria to leave the defending champions on the brink of a group-stage exit from the Africa Cup of Nations in Cameroon.
Esteban Obiang slid in at the far post to convert a flick-on and net the only goal with 20 minutes left in Douala.
Algeria has just one point from their opening two games and must beat Ivory Coast in their final Group E game to have a chance of reaching the last 16.
The north Africans had two goals ruled out in what was a scrappy encounter.
The result ended Algeria’s unbeaten run at 35 matches, two short of Italy’s world record set last year.
Equatorial Guinea reached the Nations Cup semi-finals as hosts in 2015 but, having qualified for the tournament by right for the first time, this will go down as one of the biggest results in their history.
Juan Micha’s side moves on to three points and is second in Group E, with Ivory Coast top on four points, Sierra Leone third on two points and Algeria bottom on one point.
The tight nature of the group will make Thursday’s final round of games fascinating, with the Equatoguineans facing the Leone Stars in Limbe at the same time as Algeria take on Ivory Coast in Douala (16:00 GMT).