Vincent Aboubakar's seventh-minute free-kick looked set to prove the difference between the sides as he put Cameroon ahead - the Porto man netting his fifth goal in his last four international outings.
However, Sibusiso Vilakazi levelled late on for Shakes Mashaba's men, who kick off their AFCON bid against Algeria on January 19.
Cameroon face Mali in their Group D opener a day later.
Elsewhere, Burkina Faso - tipped by many as potential outsiders to lift the trophy - completed a resounding 5-1 triumph over Swaziland.
The visitors went ahead in the 10th minute, but Burkina Faso swiftly drew level and ultimately went into the break 2-1 up.
Coach Paul Put introduced Aristide Bance at the break and he looked lively as Burkina Faso added three more in the second half, with the HJK man scoring the fifth from the penalty spot.
Congo's AFCON warm-up with fellow qualifiers Cape Verde ended in disappointment as they were beaten 3-2.
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