Germany-based Eric Maxim Choupo-Moting scored the winner at a packed national stadium in Yaounde, converting an early second-half penalty after he had been fouled.
Although eight of the original Congolese squad did not show up, they impressed during the first half only to be denied by several excellent saves from goalkeeper Carlos Kameni. Victory came as a relief for France-born Cameroon coach Denis Lavagne after troubled times on-and-off the field for the Indomitable Lions, who appeared at the 1982, 1990, 1994, 1998, 2002 and 2010 FIFA World Cup tournaments.
Meanwhile, an Emmanuel Adebayor-inspired Togo and Libya are the other teams in Group I and are set to meet on Sunday in Lome.
Central African Republic celebrated a first FIFA World Cup qualifying victory after a goal in each half from Foxi Kethevoama earned a 2-0 win over Botswana in Group A. Kethevoama, on loan to Kazakh outfit FC Astana from a Hungarian club, opened the scoring on 18 minutes and struck again early in the second half to give the Wild Beasts an early lead in a pool completed by South Africa and Ethiopia.