Both teams are tied on four points although South Africa have a better goal difference.
South Africa drew 0-0 with Lesotho in the first game before bashing Mozambique while Zambia who also started on a barren draw against Mozambique beat Lesotho 1-0.
A draw in today’s match will put Zambia at the brink of elimination.
The Tenant Chilumba-drilled side needs to fight for if they are to keep alive their hopes of defending the title they won last year.
The clash is set for 11:00hours GMT at St Francois Xavier Stadium.
A draw will be enough to see South Africa finish above the defending champions and take top spot in the pool, at the same time likely ousting Zambia from the competition unless their five points would be good enough for the best runner-up spot.
Mozambique and Lesotho will clash in the other group B that seems more of a formality game.