Senegal and South Africa booked the two other semi-final slots, joining hosts Zambia and Guinea to complete the quartet for the semi-finals and the FIFA U-20 World Cup in Korea Republic.
Senegal beat Cameroon 2-0 in Ndola in the Group B ultimate match on Sunday, whilst South Africa accounted for Sudan 3-1 at the same time in Lusaka.
Per the results, Senegal topped Group B with seven points, South Africa on six points with Cameroon and Sudan on three points and one each respectively.
Host Zambia will face South Africa in the first semi-final on Wednesday in Lusaka, whilst Senegal battles Guinea 24-hours later in Ndola.
Needing nothing short of victory to ensure their continuous stay in the competition, the Cameroonians were unsettled by the opener scored by Senegalese forward Ibrahima Niane on the stroke of half time.
Three minutes after recess, Krepin Diatta scored the second with a shot that Cameroon goalie Simon Loti failed to stop from entering the net.
The Cameroonians fought hard but even a consolation remained elusive allowing Senegal passage into the last four for the second successive time.
Elsewhere in Lusaka, Phakamani Mahlambi gave South Africa an early lead on 13 minutes before Khaled Osman levelled for Sudan on 24 minutes.
A spirited second half performance from Amajita saw them score twice through Grant Margeman on the hour mark and Sibongakonke Mbatha six minutes later.