Benjamin Corgnet's clinical finish in the first half and Mevlut Erding's penalty in the closing stages saw Les Verts move to 30 points with their ninth win of the season.
Nantes threatened an equaliser in the closing stages of the first half but the home side were good value for the three points.
They sit above Bordeaux - who travel to Marseille on Sunday - on goal difference, while moving one point clear of Nantes.
At the other end of the table, Sochaux secured an emotional first win for coach Herve Renard more than two months into his reign to revive hopes that they can dig themselves out of trouble in the second half of the season.
Renard, who took over the club in early October, had only seen them earn three points from his first nine games but they doubled that tally on Saturday after Cedric Bakumbu netted a 71st minute winner in a 2-1 victory.
Bakumbu had given the hosts the lead from the penalty spot in the 17th minute but Romain Alessandrini had levelled with another spot-kick four minutes before the break.
The win lifts Sochaux off the foot of the table although it is unlikely Renard will be getting carried away as they go into the winter break still six points from safety.
Replacing Sochaux at the foot of the standings are AC Ajaccio, who were thumped 4-1 as Reims ran riot in the second half with all four goals coming in an 18-minute spell.
Gaetan Charbonnier netted a quick-fire brace before Eliran Atar and Floyd Ayite scored either side of Eduardo's consolation as Hubert Fournier's side moved up two places to seventh in the table.
Eric Bautheac scored twice in 10 minutes as Nice claimed a 3-1 victory over close rivals Evian.
Cedric Mongongu had put Evian ahead in the 27th minute from the penalty spot but a quickfire second-half double by Bautheac gave Nice the edge, before Alexy Bosetti wrapped up victory with the home side's third goal in the 86th minute.
The result sees Nice climb to 14th place in the overall standings, nine points clear of the bottom three, while Evian remained in 16th place.
Toulouse and Guingamp shared the points as the goalless scoreline failed to do justice to an entertaining clash, while it was the same scoreline on Corsica in the match between Bastia and Montpellier, the result giving Rolland Courbis his first point since taking charge of Montpellier for a second time.