Nigeria has lost a competitive home game for the first time in 33 years as they began their African Nations Cup title defence in disappointing fashion with a 3-2 qualifying defeat by Congo in Calabar on Saturday.
French-born striker Thievy Bifouma scored twice and captain Prince Oniangue grabbed the other goal as Nigeria lost at home in a competitive fixture for the first time since being beaten 2-0 by Algeria in a World Cup qualifier in Lagos in 1981.
They had never lost before in a home qualifier in the Nations Cup.
Ivory Coast came from behind to beat Sierra Leone 2-1 with two goals in five minutes, and Ghana had to fight for a 1-1 draw at home to Uganda as some of the continent's top teams were given tough workouts. Cameroon and Algeria, Africa's other two representatives at the World Cup, both won.
Nigeria was ahead through defender Efe Ambrose's 13th-minute goal in Calabar. Prince Oniangue equalized two minutes later and a Thievy Bifouma double put the game out of the African champions' reach in the biggest surprise of the round.
Substitute Gbolahan Salami scored in the final minute of normal time, ultimately only a consolation for Nigeria after it could not make six minutes of injury time count.
Republic of Congo made it to this stage of qualifying only as a replacement for Rwanda, which was disqualified. Nigeria dropped behind early pace-setters South Africa and Republic of Congo in Group A before travelling to play South Africa next week.
Guinea leads Group E after beating Togo on Friday night.
Algeria, Africa's top-ranked team, beat Ethiopia 2-1 to start the decisive competition for Morocco 2015 with three points. Cameroon won 2-0 in Congo in its first game since its disastrous World Cup in Brazil.
El Arabi Soudani and Yacine Brahimi put Algeria ahead in Addis Ababa after absorbing early pressure. Saladin Said, who had gone close twice in the first half before Algeria went ahead, could only score a consolation for the Ethiopians with a penalty in the fifth minute of injury time.
Cameroon began life without retired striker Samuel Eto'o by rebounding from its three losses at the World Cup with an impressive win in Congo after Clinton N'jie gave the visiting team the lead in first-half injury time and Vincent Aboubakar added a second late on.
Cameroon leads Group D on goal difference from Ivory Coast.
Zambia, the 2012 African Cup of Nations winner, began with a 0-0 home draw with Mozambique, a major disappointment for the Zambians after the home strikers wasted a succession of chances.
Cape Verde took advantage of Zambia's slip to win 3-1 at Niger and lead Group F. Cape Verde was 2-0 up after 14 minutes to cruise to victory in Niamey.
Burkina Faso beat Lesotho 2-0 and Gabon edged Angola 1-0 in Group C.
The final qualifiers see 28 teams split into seven groups, with the top two in each group winning places at the Cup of Nations in Morocco in January and February. There is also a place for the best third-placed team.
South Africa, Senegal and Guinea all opened the three-month qualifying competition with victories on Friday.