In the final tie (Saturday, 20:00 GMT), Cape Verde are bidding to reach a first-ever semi-final against a South Africa side who upset Morocco and are chasing a first title since 1996.
The well-drilled islanders have played some stunning passing football at times and their eight goals have come from seven different players – with a late penalty from captain Ryan Mendes sealing progress against Mauritania.
The Blue Sharks skipper possesses technical qualities, Jovane Cabral has plenty of trickery on the ball and former Manchester United forward Bebe has long-range free-kicks in his locker.
“We have progressed a lot over the years,” Mendes said. “A semi-final would be something exceptionally historic for our country.”
South Africa lost their opener against Mali but have kept three successive clean sheets since, with the latest of those in their surprise 2-0 triumph over the Atlas Lions.
Midfielder Teboho Mokoena has impressed among their core drawn from Pretoria-based club side Mamelodi Sundowns, while Bafana Bafana coach Hugo Broos can call on the experience of guiding Cameroon to glory in 2017.
“Broos has taken more Sundowns players because he understands those players have experience playing against different opponents from across the continent,” former South Africa midfielder Aaron Mokoena told BBC Sport Africa.
“He realised that the synergy is important.”
Opta’s artificial intelligence prediction model gave Angola and Cape Verde less than a 1% chance of lifting the trophy before the finals began, but if both countries pull off further upsets then they will meet on Wednesday for a place in the final.
Viewers in the UK can watch DR Congo vs Guinea (Friday, 20:00 GMT) and Cape Verde vs South Africa (Saturday 20:00 GMT) on BBC Three, iPlayer and the BBC Sport website.