After stopping four flare-ups during the night, 450 firefighters had managed to bring the blaze, which was just 19 kilometres from the French Riviera city, under control on Tuesday morning.
But not before it had destroyed 120 hectares of forest and a car scrapyard.
The flames reached three homes, without causing serious damage or harming any residents, but three firefighters were overcome by fumes.
"It's one of the most difficult fires I've had to handle in my whole career," firefighters' officer Olivier Riquier told local paper Nice Matin.
Winds blew toxic fumes into the city, even reaching the seaside Promenade des Anglais, on Tuesday morning, and planes continued to dump water and flame retardant on the scene.
Corsicans flee to beaches
The south of France and Corsica are hit by wildfires every year and high temperatures and winds have caused a number in the last few days, with 800 hectares of forest destroyed near Aix-en-Provence at the weekend.
A blaze destroyed some 200 hectares of scrubland near the southern Corsican town of Bonifacio on Monday but calmed overnight.
Local people were confined to two beaches as emergency services tackled the conflagration.
The warm weather was forecast to continue on Tuesday, with storms predicted in the north-west and the west.