Pierre Webo missed the game's best chance to give the Indomitable Lions the edge in a scoreless first leg, with the return fixture to come in Yaounde on Thursday.
In an evenly-matched encounter, Pierre Webo spurned the best chance to win the game for the visiting side, meaning that the Indomitable Lions will approach Thursday's fixture in Yaounde on an even basis.
After speculation surrounding Samuel Eto'o's international future, the forward was named in Cameroon's starting XI by Volker Finke, but the Chelsea man rarely threatened, leaving all to play for in the second leg.
The home side began brightly as Yassine Chikhaoui forced Charles Itandje into a smart stop with a fierce drive from inside the area in the opening minute.
Houcine Ragued and Saber Khalifa both saw headers saved by Itandje shortly after Chikhaoui's early opportunity as Tunisia continued to apply the pressure.
After Eto'o saw a tame attempt easily saved by Moez Ben Cherifia, Wissem Ben Yahia's dipping effort had Itandje scrambling once more to keep the scores level.
Jean Makoun almost put the visiting side ahead four minutes from the break, but put his effort the wrong side of Ben Cherifia's post.
Cameroon, seeking to book a place in its seventh World Cup finals, also struggled to assert itself after the break, with Ben Youssef heading a Sameh Derbaly cross just wide after 55 minutes.
Webo then missed the best chance of the game as he failed to convert an Allan Nyom delivery in front of an open goal with 22 minutes remaining.
Though the game became more open in the latter stages, neither side could strike late on, as the tie remains finely poised ahead of the second leg.