The French-born midfielder struck a firm shot from just outside the penalty area to separate the West African rivals, the last of the 16 teams at this year's tournament in Equatorial Guinea and Gabon to get their campaigns underway
The 29th-minute goal came after a strong run from Modibo Maiga who cut the ball back for Traore to blast home as Seydou Keita scampered out of the way.
On a night of plentiful chances, it was the only accurate finish as both sides traded blows in a high tempo game that contrasted with some of the pedestrian efforts in the first four days of the continental championship.
Guinea made the most opportunities, notably in the first 25 minutes with Ismail Bangoura going close, and in a dominant second-half display as they attempted to get back into the game.
Coach Michel Dussuyer introduced three young substitutes - including debutant Abdoul Razzagui Camara - to increase the pace of his attack but was let down by poor finishing.
Substitute Ousmane Barry missed a header in front of goal provided by Camara's cross and former captain Pascal Feindouno twice shot narrowly wide.
Mali's win set up a mouth-watering meeting with Ghana on Saturday.
Ghana beat Botswana 1-0 in Franceville earlier on Tuesday.
