World Cup-bound Algeria will be the first side eliminated from the African Nations Cup if they lose against Mali in Luanda on Thursday.
Algeria, in the same group as England at this year's World Cup in South Africa, suffered a shock 3-0 defeat by Malawi in their opening Group A match on Monday and will be condemned to an early exit if they lose again in their second group game.
Algeria take on Mali (1600 GMT) in the first of two matches at Luanda's November 11th Stadium on Thursday, followed by the meeting between hosts Angola and Malawi (1830).
Angola have to put behind them a spectacular capitulation in Sunday's opening match when they squandered a four-goal lead to share the points with Mali.
The hosts are now also in danger of failure in a tournament on which some $1 billion has been spent on building stadiums, roads and hotels.
Malawi are the group leaders after their upset win on Monday, which set the tone for several more surprises at the tournament.
On Wednesday, Cameroon failed to live up to their billing among the pre-tournament favourites as they lost 1-0 to Gabon. Tunisia and Zambia drew 1-1 in Wednesday's other Group D match in Lubango.
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