Leading African football nations Cameroon, Senegal and South Africa face challenges of varying difficulty this weekend as 2016 African Nations Championship (CHAN) qualifying reaches a climax.

Cameroon team are away to Congo Brazzaville after a 0-0 draw last weekend in the first leg of a first round tie in a competition restricted to home-based players.

Senegal, a top-10 ranked African nation like Cameroon, have home advantage as they attempt to overcome a 2-0 deficit against Guinea.

South Africa, outside the top 10 but still a prized scalp, are in the bleakest situation having fallen 2-0 at home to Angola.

Cameroon, who qualified for only one of the previous three CHAN tournaments, could not penetrate the ultra-defensive Congolese in Yaounde. "Congo played a beautiful game," conceded Cameroon coach Martin Ndtoungou Mpile. "Instead of criticising my boys for not scoring, let us give credit to our well-organised opponents."

The Congolese will be extra keen to succeed after recent disappointments in Olympic Games qualifying and the African Games finals, which they hosted. Goals from Aboubacar Mouctar Sylla and Aboubacar Iyanga Sylla have offered Guinea hope of a first appearance at the 16-nation tournament, which Rwanda host in January and February.

Caretaker South Africa coach Thabo Senong remains optimistic despite facing a desperate situation after Mateus Da Costa and Manuel Afonso scored for Angola in Johannesburg.

"We have left ourselves with a steep mountain to climb," Senong admitted, "but are not feeling like lambs going to the slaughter. "Our aim is to fight and fight hard, take the fight to the Angolans and create an unlikely result."

South Africa have been handicapped by the refusal of clubs to release stars, forcing Senong to pick out-of-favour first and second division players. Nigeria, third behind Libya and Ghana at the 2014 CHAN, are well placed with goals from Bature Yaro and Gbolahan Salami creating a 2-0 lead over Burkina Faso.

Zimbabwe, one of three countries to feature in the three previous African Nations Championship tournaments, are in Lesotho defending a 3-1 lead. "I did not want to concede at home, so hard work lies ahead for us," warned Zimbabwe coach Kalisto Pasuwa. "Playing away is always difficult and we must be on our guard."

Rodrick Mutuma will require close attention, having scored twice within nine minutes to turn the first leg in favour of the Zimbabweans.

Uganda are another country with a two-goal advantage, thanks to goals against Sudan in Kampala from Frank Kalanda and captain Farouk Miya.

"We have one foot in the finals," said Serbia-born Uganda coach Milutin "Micho" Sredojevic. "We have the letter inviting us to the finals and we are going to Sudan for the stamp."