For much of the encounter, Guinea looked an equal match for their hosts, who are bidding to make their fifth appearance at the World Cup, although they did survive a few frights to hang on with the scores locked at 0-0 at the break.
Visiting coach Lappe Bangoura shuffled his pack early in the second half, replacing Queens Park Rangers forward Idrissa Sylla with Standard Liege Mohamed Yattara, although it was their opponents who broke the deadlock moments later.
Abdennour met Ali Maaloul’s corner to give Tunisia the lead in the 58th minute, and while Guinea did manage to direct several efforts at goal as they went in search of the equalizer, although often, their forays forward left gaps at the back which the Carthage Eagles looked to exploit.
Eventually, Guinea left one gap too many, as Tunisia countered from a Syli Nationale corner and Hamza Lahmar played in Darmstadt forward Anis Ben-Hatira who calmly slotted home a low winner in the 80th minute.
The victory moves the North Africans second in Group A behind the Democratic Republic of Congo, who are top of the pool on goal difference after demolishing Libya 4-0 in Kinshasa on Saturday.