French-born Itandje, who plays in Turkey and has been a back-up keeper at Liverpool, made a series of spectacular stops from as early as the opening 10 seconds to swing the advantage Cameroon's way before the return leg in Yaounde on Nov. 17.
He was called into action from the opening whistle at the Rades Stadium, blocking with his feet when Tunisia captain Yassine Chikhaoui was set up with a good early chance.
Another important block in the fourth minute denied Houcine Ragued at the back post as Itandje was left exposed by his defence.
Then came a tip over the top of the crossbar to deny a rasping shot from Wissem Ben Yahia followed by another instinctive parry away of a diving close-range header from Chikhaoui.
Midway through the second half Itandje denied defender Alaeddine Yahia as hosts Tunisia threw players forward in an increasingly desperate bid to force a goal.
Cameroon had two good chances to grab a win, first when Jean Makoun missed the target from close range after being teed up by captain Samuel Eto'o and then when Pierre Webo failed to scramble home the ball when he was unmarked at the back post.
The draw followed a 2-1 away win for Nigeria against Ethiopia in their playoff first leg in Addis Ababa earlier in the day.
Burkina Faso beat Algeria 3-2 and Ivory Coast overcame Senegal 3-1 on Saturday. Ghana host Egypt on Tuesday.
The five playoff winners will qualify for next year's finals in Brazil.
- Sports & Recreation
- Yassine Chikhaoui
- Wissem Ben Yahia