Striker Eric Choupo-Moting scored three minutes from time as former winnersCameroon scraped a 1-0 victory in Guinea-Bissau on Wednesday at the start of their 2013 African Nations Cup qualifying campaign.
Four-times champions Cameroon, keen to revive flagging fortunes against weaker opposition, produced a laboured display in the first round first leg match.
Elsewhere, Democratic Republic of Congo eased to a 4-0 triumph in the Seychelles while Cape Verde Islands won by the same scoreline in Madagascar.
Alain Kaluyituka scored twice for Congo who were ahead after just eight minutes.
Dady and Ryan Mendes netted first-half goals to set up victory for Cape Verde who are emerging as an improving force in African football.
New cap Sofiane Feghouli, the Valencia striker, grabbed a 57th-minute winner as Algeria came from behind to defeat Gambia 2-1.
Former champions Nigeria, forced to take part in the early stages of qualifying after missing out on the 2012 finals, were held to a goalless draw in Rwanda despite the return of striker Yakubu Aiyegbeni.
Yakubu, who had a goal ruled out for offside, was playing for his country for the first time since the 2010 World Cup and partnered Peter Odemwingie in attack.
Emmanuel Adebayor was a no-show as Togo lost 2-1 in Kenya, Allan Wange getting the winning goal midway through the second half.
Adebayor failed to arrive for the match in Nairobi, much to coach Didier Six’s frustration.
Burundi captain Valery Nahayo struck late as his side won 2-1 against a weakened Zimbabwe who left behind their coach and several players implicated in an alleged match-fixing scandal.
There was another win for tiny Sao Tome and Principe, who overcame Lesotho in a preliminary-round tie in January, as they beat Sierra Leone 2-1.
The return legs are in June. The winners advance to the final round of qualifiers in September and October and from there the winners will be drawn with the teams who competed at the recent Nations Cup finals.