It was the bottom-placed team that took the lead via Julio Tavares in the 22nd minute, with Gabon midfielder, Didier Ndong providing the assist.
The hosts responded seven minutes later through Kasper Dolberg, with Atal’s Algerian teammate, Adam Ounas, giving the assist.
Atal then went on to score the winner two minutes after the restart, volleying home a fierce right-footed shot on the left side of the 18-yard area.
The victory is Nice’s fourth of the season in six games, which sees them occupy second place with 12 points, same as league leaders, Paris Saint-Germain, who have a superior goal difference and have played a game less.
23-year old Atal was widely linked with a move to Chelsea until the London club received a two-window transfer ban after Fifa adjudged them guilty of breaking the rules on signing young players.
The Blues transfer ban will be over by the end of the season where it remains to be seen whether the £35 million-rated full-back will still be on the club's radar.