Algerian striker Mohamed Youcef Belaïli's early second half strike proved to be the difference between the two top teams as the Desert foxes held on to the slender lead by putting up a resilient defensive performance.
Senegal's streak of defeats against Algeria continues, as they lost to their familiar opponents yet again.
Though Lions of Teranga looked dangerous every time Mane got the ball at his feet, Nice left-back Youcef Atal deserves a pat on the back for holding his ground against the fleet-footed forward.
Apart from the Liverpool forward, Senegal didn't really have much to offer in the attacking third throughout the game. This came back to bite them in the latter stages of the match as the Algerians preferred to sit back and defend their one-goal lead.
With this crucial win, Djamel Belmadi's men have sealed their place in the knockout stage of the competition and may as well choose to rest their key players for the last group stage fixture against minnows Tanzania.
#5 Sadio Mane lit up the field with his dangerous runs but failed to make an impact in his first game
As expected, Mane put in a really inspired performance for his nation and despite their loss, his incredible form bodes well for the team that has never lifted the continental trophy.
He was all set to go from the kick-off whistle and led the Senegalese charge in the starting phase of the game as they looked to be the side in control.
Though he didn't get the required support from his attacking partners during the game, he kept trying to pull one goal back, right until the last kick of the match and came close when his header in the dying moments of the game just glazed past the bar.
He is yet to open his account at the competition, but it seems imminent that he will find the back of the net in the in their must win match against Kenya next week.