Super Eagles and Benin are widely expected to book their passage to the 2021 AFCON to be hosted by Cameroon next year, but Sierra Leone cannot be discounted from sneaking through in the last two rounds of the qualifiers.
Nigeria lead Group L with eight points from four matches, while Benin are closely behind on seven points.
Sierra Leone, who must be buoyed by the draws they achieved with star-studded Nigeria, are third on three points and Lesotho are bottom of the standings with two points.
Lesotho will host the Leone Stars early on Saturday, before Benin take on the Super Eagles at home in Porto-Novo.
The Crocodiles from Maseru forced Sierra Leone to a 1-1 draw in the reverse tie in Freetown.
A win for the West Africans in Southern Africa will keep them in the hunt for a place at the AFCON proper as that will take them to six points with their final game against Benin in Conakry, Guinea, on Tuesday, March 30, assuming a far greater importance.
Nigeria need a point from the two matches to book their passage to Cameroon, while Benin will go through with a win over their more illustrious neigbours and not have to fret over their qualification right up to the last day of this campaign.
The Eagles had to fight back from an early Stephane Sessegnon strike in Uyo two years ago before they could stop the Squirrels 2-1 in Nigeria.
Benin coach Michel Dussuyer said they were disappointed by that loss, while confident they can pull off a famous home victory this weekend.
