Tunisia took a 15th-minute lead and looked comfortable through the first half but allowed Gabon an equaliser soon after the break and might well have lost had their opponents been sharper in front of goal.
Saber Khlifa outjumped the advancing goalkeeper to score Tunisia's first but Johan Lengoualama equalised in the 51st minute when he took advantage of some sloppy defending.
Gabon came close to a second goal two minutes later when Martin Essono shot just wide after a quick breakaway put him clear of a pedestrian Tunisia defence.
The draw for Tunisia follows a 1-1 draw against fellow finalists Ethiopia in Doha on Monday. They will pay Ghana in Abu Dhabi on Sunday before heading to the Nations Cup in South Africa where the play in Group D against Algeria, Ivory Coast and Togo.