Mali and Ghana both had 1-0 wins in their opening African Cup of Nations matches in Franceville to share top spot in Group D.
Lyon defender, and Ghana captain, John Mensah gave his team a positive start as one of the tournament favourites with a first-half goal against Botswana, but turned from hero to villain as he was shown a straight red card midway through the second period.
Meanwhile, with 30 minutes on the clock, Mali grabbed the only goal of the game when Bakaye Traore's ferocious drive from the edge of the box found the back of the net, taking a deflection from a Guinea defender along the way.
In the early game, Ghana, the four-time African champions, dominated time on the ball, especially in the first half, but were unable to convert aside from Mensah's goal.
Mensah put Ghana in the lead in the 25th minute, bundling the ball in from a corner kick taken by Emmanuel Agyemang-Badu.
The Ghanaians kept pushing forward for goals but the Botswanian rearguard were staunch in defence.
Botswana had a gilt-edged chance to equalise when striker Jerome Ramatlhakwane was charging towards goal and was one-on-one with the 'keeper when Mensah challenged from behind to earn his red in the 66th minute.
It proved to be Botswana's best chance of the match, but they failed to seriously threaten for the remainder.
Against Mali, Guinea could have taken the lead in the opening minute. Ibrahima Traore picked the ball up and smashed a powerful drive towards goal from 30m out which required Soumbeila Diakite to parry the ball to safety.
Guinea were on the attack again in the 18th minute when a quickly taken free kick enabled Lass Bangoura to cross the ball into the box to his namesake, Ismael Bangoura, who did well to get his head to the ball yet Diakite's acrobatic stop kept the scores level.
Despite their positive start, Guinea fell behind on the half hour mark. After a free kick into the box, the ball fell to Bakaye Traore on the edge of the penalty area and the Nancy midfielder unleashed an unstoppable drive high into the net via a deflection from Habib Balde.
Michel Dussuyer's men could and perhaps should have been level in the 34th minute. Ismael Bangoura was played through on goal by Pascal Feindouno yet the Al Nasr striker was denied once again from close range by the keeper who made a smart block to preserve his side's lead at half-time.
Both sides were sluggish on the early stages of the second period yet Guinea came close to equalising in the 66th minute.
Substitute Abdoul Camara whipped an inviting cross into the box yet Ousmane Barry failed to get his head to the ball from six yards out - the Etoile man coming within inches of scoring.
Next up for Guinea is a meeting with Botswana on Saturday, while Mali face a crunch encounter against Ghana in the later game.