Mali's Eagles joined Ghana at the top of Group D after beating Guinea 1-0 in a tight affair in Franceville.
Bakaye Traore scored the only goal after 30 minutes as his powerful strike from the edge of the area deflected past Guinea goalkeeper Naby Yattara.
Guinea threatened through youngster Alhassane Bangoura, Ibrahima Traore and Ismael Bangoura but could not find a way past an obdurate defence.
Group D is topped by Mali and Ghana, who beat Botswana - also 1-0 - earlier.
Wednesday's late game meant that all 16 teams at this year's Africa Cup of Nations had been in action, with every match managing to produce a winner so far.
After the heat of the earlier Franceville had lifted, the stage was set for a West African derby which had a much faster pace - with Guinea enjoying the brighter start.
After 18 minutes, forward Ismael Bangoura rose at the back post to head a deep cross back across goal, only for Mali goalkeeper Soumaila Diakite to pull off an athletic save.
Minutes later, highly-rated Guinean youngster Alhassane Bangoura - who's been linked with Real Madrid despite being just 19 - raced clear before rasping an angle drive into the side netting.
Yet Guinea were caught on the hop after half an hour as Mali scored against the run of play with their first attack of note.
Striker Modibo Maiga, whose Newcastle United move broke down because of knee concerns, got to the byeline before his pullback eventually found the onrushing Traore whose powerful drive took a deflection as it whistled past Yattara.
The Syli Nationale almost replied immediately as Bangoura went on a mazy run, jinking inside one player before cutting past another, only to fire into goalkeeper Diakite.
Ibrahima Diallo thought he had won Guinea a penalty shortly before the break but his reward for being clipped by Mahamadou N'diaye was an ill-deserved booking for simulation.
Mali fans could say the decisions evened out as Guinea's Dianbobo Balde appeared lucky to stay on the pitch after hauling down Cheikh Tidiane Diabate to deny the Eagle a clear goalscoring opportunity.
The game suffered midway through the second half as coaches Alain Giresse (Mali) and Michel Dussuyer (Guinea) rang the changes, but Guinea substitute Abdoul Razzagui Camara threatened at one end while Garra Dembele could have scored at the other.
Late on, Pascal Feindouno forced Diakite to tip over the bar but Guinea could not find the equaliser they deserved as Mali's defence, expertly led by captain Cedric Kante, held on.
The Eagles had come into this year's finals with numerous injuries, losing two players in the last week while Mahamane Traore was almost replaced after suffering a foot injury (only for Malian officials to have a last-minute change of heart).
They now face Ghana in their next game in Franceville, shortly after both Botswana and Guinea go in search of their first Group D points on Saturday.