The Etoile Sahel midfielder let fly with an unstoppable effort eight minutes from time to help Carthage Eagles escape a defeat in their CAN opener.
Tunisia went ahead early in the game through Issam Jemaa before Moustapha Sall drew Senegal level just before halftime.
Diomansy Kamara added the second for the Teranga Lions six minutes past the hour mark but his side's hopes of securing an important win were dashed by Traoui.
Angola tackle South Africa in the other group game later on the day.
Tunisia keeper Hamdi Kasraoui was given an early scare by teammate Radhouene Felhi.
After two minutes, the Etoile Sahel defender tried to clear El-Hadji Diouf's free-kick but his mis-headed attempt narrowly missed the target.
It was Tunisia who opened the scoring seven minutes later after a swift counter attack.
Jemaa superbly exchanged passes with Wissam El Bekri and hit a left-footed low strike into the bottom corner of the net.
Senegal striker Mamadou Niang came close to leveling the score midway through the first-half.
He received a deft pass on the edge of the area, turned and drilled a low shot that went inches wide. Kasraoui was left stranded.
Sall grabbed the equalizer in the first-half's additional time after capitalizing on a dreadful error by the below-par Radhi Jaidi.
The Birmingham defender cleared a through pass into the path of Sall, who went clear on goal and slotted home past Kasraoui.
Senegal had the upper hand in the second-period as they threatened Tunisia on several occasions while the North Africans rarely tested Tony Sylva.
Four minutes after restart, Kamara latched onto Diouf's through pass and went one-on-one but his close-range effort went just wide.
Niang squandered a golden opportunity on the hour mark when he was picked out totally unmarked in the six-yard box.
The Marseille man connected with Frederic Mendy's cross but shot horribly wide with the goal at his mercy.
The pressure finally paid off in the 66th minute when Kamara poked home from inside the area after a goal-mouth scramble. Tunisia defenders positioned very poorly.
Traoui secured a precious equalizer for Tunisia against the run of play when he smashed an unstoppable bullet from 30 yards into the top corner of the net.