The 4-0 victory in Kinshasa on Sunday leaves the Congolese with an almost insurmountable lead as Anderlecht striker Dieumerci Mbokani scored twice and Deo Kanda and Issama Mpeko add the others after a goalless first half.
It was the biggest win of the 15 final round, first leg qualifiers played across the continent at the weekend and will likely see the Congolese, winners in 1968 and 1974, back at the finals after missing the last three tournaments.
Substitute El Arbi Hillel Soudani scored two minutes from time to give Algeria a 1-0 away win over Libya in their tie played in neutral Casablanca and also a massive advantage for the return leg.
Algeria’s pressure paid off with a cleverly worked goal for the Portuguese-based striker, who has now netted five in his seven international appearances. But the win was followed by a mass brawl on the pitch between the two sets of players at the final whistle.
Mozambique pulled off a surprise 2-0 home win over a star-studded Morocco side to give themselves a good chance of also making the finals. They had been given little chance when the draw was made but goals from Miro and Dominquez ensured a defendable lead for next month’s return match.
The result puts further pressure on Morocco coach Eric Gerets, already feeling the ire of the local media and fans after a disappointing start to 2014 World Cup qualification.
Zimbabwe, another neighbour of 2013 hosts South Africa, exceeded expectations by beating Angola 3-1, scoring liberally in the first half but giving up an away goal near the end of their game in Harare.
Their win came despite the absence of their Bundesliga based striker Knowledge Musona, who failed to pitch for the game. Ibrahim Yattara scored the only goal as Guinea struggled at home to beat Niger. They now take a precarious 1-0 lead to the return match in Niamey next month.
On Saturday, Cote d’Ivoire took a 4-2 lead over Senegal after the home leg of their qualifier in Abidjan.
Didier Drogba scored from the spot to go with goals for Salomon Kalou, Max Gradal and Gervinho.
Hosts Liberia fought back to draw 2-2 with Nigeria in Monrovia on Saturday night, but the lackluster Super Eagles will still feel they should complete the job in the home fixture next month.
Cape Verde caused one of the biggest surprises in recent times with a 2-0 victory over Cameroon in Praia. The victory is arguably the biggest in the history of the country and confirms the downward spiral of the Indomitable Lions.
Cape Verde’s goals came via Ricardo, who netted midway through the first half, and Djaniny, who added a second just past the hour-mark.
Ghana were 2-0 victors over Malawi with goals from Christian Atsu and Anthony Annan, but it was a poor performance from the Black Stars.
African champions Zambia were also far from convincing after they could manage just a 1-0 home win over Uganda. Chipolopolo took the lead in the 21st minute through captain Christopher Katongo, but could not add further to their tally and face a stiff test in Kampala next month.
A frantic end in Libreville saw Togo's returning star Emmanuel Adebayor cancel out Daniel Cousin’s 85th minute header for Gabon to give the Togolese the edge going into the home leg after this 1-1 draw.
Mali have completed a comfortable 3-0 victory over Botswana in Bamako. Cheick Diabate put Mali ahead on 27 minutes from the penalty spot, before Tenima Enday added a second just before the hour mark.
That lead was made more comfortable by Modibo Maiga scoring again for the hosts 20 minutes before the end in what was ultimately a routine victory.
Sierra Leone and Tunisia played to a 2-2 draw in Freetown, while Sudan profited from two late penalties as they defeated Ethiopia 5-3 in Omdurman.