The result lifted Nantes up to 14th on 37 points, 12 above the relegation zone.
Emiliano Sala died two days after Cardiff had signed the Argentinian striker for a club record US$19.7million from Nantes.
Sala's contract was rejected by the Premier League and he had not signed a new one before perishing in the plane crash.
A successful negligence claim against Nantes could reduce the transfer fee that Cardiff owes the French club.
A public vigil was held in a gymnasium in Progreso, the modest village in the province of Santa Fe which Sala left as a teenager to forge a career in Europe.
British media reports that the Welsh club has so far been unwilling to release the transfer fee, despite a demand from Nantes.
Attempts to recover the aircraft were unsuccessful due to poor weather conditions.
Investigators plan to launch an underwater seabed search for aircraft wreckage.
The light aircraft transporting the 28-year-old striker disappeared from radar around 20 km north of Guernsey on Monday night.
Rescuers' hopes rest in the possibility that the passengers are in a life raft, which has so far evaded detection.
Sala, 28, is feared dead after contact was lost with the aircraft taking him back to Wales.
World Cup star Mbappe stole in at the far post in the 67th minute for his 13th league goal of the season, making him France's top scorer.
Jonathan Ikoné's goal helped Lille to a 2-1 victory over Nantes.
The officer who shot Aboubakar Fofana has been charged with manslaughter after admitting he had falsely claimed self-defense.
Cars and buildings were set alight Friday in a third night of rioting in western France over the fatal police shooting of a young man.
The French government on Wednesday called for calm after police in the western city of Nantes clashed overnight with protestors.