Veteran striker Eto'o called time on an 18-year international career last month but coach Volker Finke - retained in his post despite a shambolic FIFA World Cup campaign in Brazil - oversaw an assured start to the new era.
Lyon forward Clinton N'jie went some way to filling Eto'o's sizeable shoes by opening the scoring on the stroke of half-time and Porto's Vincent Aboubakar sealed the points in the 82nd minute.
DR Congo's efforts were somewhat hampered by captain Youssouf Mulumbu sustaining a hamstring injury midway through the first-half.
Cameroon's fellow Group D heavyweights Ivory Coast secured a 2-1 comeback win against Sierra Leone in Abidjan.
However, Seydou Doumbia made an instant impact, coming off the bench to level matters from Serge Aurier's 63rd-minute cross, before Gervinho drilled home a low winner five minutes later.
The shock result of the day came in Group A as Nigeria continued a turbulent period on and off the field with a 3-2 loss at home to Congo.
Thievy Bifouma finished off a splendid team move in the 40th minute and the same player netted a second-half penalty after being fouled by Ogenyi Onazi to give Congo breathing space.
South Africa are up next for Nigeria, providing the latter's Football Association can avert a global ban by agreeing to FIFA's terms over an ongoing governance dispute regarding political interference.
Algeria built on their impressive World Cup showing with a 2-1 win in Ethiopia - Frenchman Christian Gourcuff's first competitive game at the helm.
Hillel Soudani and Yacine Brahimi were on target either side of half-time before Saladin Said netted a consolation penalty in stoppage time for the home team, whose own coach Mariano Barreto also oversaw a maiden competitive outing.
Asamoah Gyan was twice denied by Denis Onyango before Tony Mawejje struck from the edge of the area to give Uganda a half-time advantage.
Andre Ayew levelled matters five minutes after the restart after Abdul Majeed Waris was fouled in the box, but Ghana could not force a win.
There was late drama in the day's final game as Yassine Chikhaoui scored a 90th-minute penalty for Tunisia to snatch a 2-1 home win over Botswana.
Wahbi Khazri scored a free-kick with 16 minutes to play before Ofentse Nato's handball presented Chikhaoui with the chance to be his nation's hero.
Cape Verde were the day's winners in Group F - Garry, Odair Fortes and Ze Luis responsible for them racing into a 3-0 lead inside 24 minutes against Niger, who could only reply through seasoned striker Moussa Maazou.
The group's other game between southern African rivals Zambia and Mozambique ended goalless.
