Mauritania, a largely desert state that have never qualified for the Africa Cup of Nations, are among 15 countries who could secure places at the 2019 tournament this weekend.
A team guided by French coach Corentin Martins will be assured of a top-two finish in Group I and qualification if they defeat bottom side Botswana in Nouakchott.
The Mauritanians, whose squad includes players from local clubs, other African countries, Europe and the Middle East, enjoy several psychological advantages over their opponents.
They travelled to the southern Africa nation for the first round of qualifying in June last year and won 1-0 through an Abdallahi Soudani goal.
While Mauritania have won three of four games in a group completed by Burkina Faso and Angola, Botswana have lost three, drawn one, and not scored a single goal in 360 minutes.
A glance at the record books will bring added gloom to the Botswanans as the only previous Cup of Nations visit to Nouakchott resulted in a 4-0 hiding 12 years ago.
Another French coach, Patrice Neveu, transformed Mauritania from whipping boys to formidable opponents by qualifying for the 2013 African Nations Championship for home-based players.
Under Martins, they stunned South Africa in a 2017 Cup of Nations qualifier and twice ran five-time African champions Cameroon close in the same group.
Algeria, Benin, Burkina Faso, DR Congo, Gabon or Mali, Guinea, Guinea-Bissau or Namibia, Ivory Coast, Morocco, Nigeria, South Africa, Tanzania, Uganda and Zimbabwe could also qualify.
Cameroon are automatic participants as hosts of the June 15-July 13 finals and Madagascar, for the first time, Egypt, Senegal and Tunisia secured slots during matchday 4.
South Africa need a win and Nigeria a draw from a Group E clash of former champions in Soweto to be certain of qualification after both missed the 2017 tournament.
An injury rules out Nigerian Odion Ighalo while South Africa chose Thulani Serero, who shunned several previous call-ups because he was not guaranteed a starting place.
– Pharaohs seek revenge –
Both countries will secure finals places irrespective of the result if Libya lose in the Seychelles, whose 188th world ranking is the lowest among the 48 teams in the competition.
Egypt against Tunisia in Alexandria is another high-profile fixture, even though they have already booked finals places from Group J.
Some of the stars from CAF Champions League winners Esperance of Tunisia and runners-up Al Ahly of Egypt have been selected as the Pharaohs seek revenge for a 1-0 loss in Rades.
Guinea and Uganda will be sure of places among the 24 finalists in Cameroon provided they do not lose at home.
Belgium-born Guinea coach Paul Put has axed midfielder Seydouba Soumah, accusing him of “lacking commitment” ahead of Group H top-of-the-table clash with the Ivory Coast.
The Ivorians, whose second Cup of Nations title came three years ago, will lack injured Crystal Palace flier Wilfried Zaha as they take on a team who beat them 3-2 in Bouake.
Uganda share with South Africa the record of not having conceded a goal in 2019 qualifying and goalkeeper Denis Onyango rates among the best in Africa.
The ‘Cranes’ will be confident of securing at least a point against Cape Verde in Kampala having beaten the tiny island state 1-0 away with Geoffrey Sserunkuma snatching a late goal.
If Uganda triumph, Tanzania, whose only previous Cup of Nations appearance was 38 years ago, can accompany them from Group K by collecting maximum points in Lesotho.
A Mali team lacking unavailable Brighton midfielder Yves Bissouma will go through from Group C should they complete a double over Gabon after winning 2-1 in Bamako.
For Pierre-Emerick Aubameyang-captained Gabon to qualify, they must triumph in Libreville and hope third-place Burundi lose away to pointless South Sudan in Juba.
Away victories for Algeria and Benin over Togo and the Gambia respectively would secure qualification from Group D while Zimbabwe need a draw in Liberia to advance from Group G.