Cameroon and Zambia will play each other in January to decide who will automatically qualify for the women's football tournament at the 2020 Tokyo Olympics.
The losers of that game will face Chile in a play-off for another place at the Games.
Unlike the men's Olympic football tournament the women's event is open to full national teams rather than under-23 sides.
A late penalty from Ajara Nchout proved to be the difference for Cameroon as they edged past Ivory Coast 2-1 on Tuesday after a goalless first leg in Abidjan three days earlier.
Hosts Cameroon had taken the lead after 28 minutes through Charlene Meyong only for Ivory Coast, who beat African champions Nigeria in the last round, to equalise shortly after half-time through Rebecca Amon.
Zambia also came through a tight game against Kenya with a 1-0 win on Monday to complete a 3-2 aggregate win.
Lushomo Mweemba at just 18-years-old scored the only goal of the game in the second-half of Monday's match in Lusaka.
It would be Zambia's first ever appearance in the women's Olympic football tournament while Cameroon played at the 2012 Games in London, where they lost all three of their games.