Former champions Zambia must defeat Cape Verde on Monday to keep alive their hopes of reaching the 2015 Africa Cup of Nations quarter-finals in Equatorial Guinea.
A win for the shock 2012 title-winners in the remote north-eastern town of Ebebiyin would secure second spot in Group B provided Tunisia win or draw against the Democratic Republic of Congo in Bata.
But a victory for the Congolese Leopards would condemn the Chipolopolo (Copper Bullets) to a second consecutive first-round exit since rocking Ivory Coast in a penalty shoot-out to lift the trophy.
Tunisia have four points, Cape Verde and DR Congo two each and Zambia one going into the final mini-league fixtures.
Amid numerous scenarios is the prospect of drawing lots to separate Cape Verde and DR Congo should they draw their matches by the same score.
Lots have been used just once before in the biennial African football showcase with Algeria reaching the 1988 knockout stage at the expense of the Ivory Coast.
“We are under pressure,” admitted Zambia coach Honour Janza, “but so are the other three teams.
“The fact that all four teams can go through to the knockout stage has set up a very interesting and tense climax.”
Zambia and Cape Verde clashed in the 2015 Cup of Nations qualifiers with both teams winning at home.
A Ryan Mendes goal gave the Blue Sharks a 2-1 win last September and Zambia won 1-0 two months later via a Ronald Kampamba strike.
“Cape Verde are a strong side and it will be a difficult fixture given that we met twice within the last four months,” conceded Janza.
“We know their style of play well and they know ours equally well.”
Zambia, who have lost injured midfielder Nathan Sinkala for the tournament, must give Emmanuel Mayuka a late fitness test.
The Southampton striker injured a groin during a 2-1 loss to Tunisia, a result that infuriated Janza and captain and midfielder Rainford Kalaba.
Janza accused his players of being egotistic and selfish in the attacking third of the pitch while Kalaba admitted he did not recognise his team as they faltered after taking the lead.
Rival coach Rui Aguas says a last-eight place is the bottom line for Cape Verde, who reached the Cup of Nations quarter-finals on their debut two years ago.
“While we want to go further this time, the minimum objective is reaching the quarter-finals,” said the former Portugal striker.
Although DR Congo have not beaten Tunisia in three Cup of Nations clashes, veteran Leopards goalkeeper Robert Kidiaba is hopeful.
“Tunisia are a formidable side, but they dare not underestimate us,” warned the 38-year-old who is the oldest footballer at the Cup of Nations.