Mario Balotelli scored twice as Nice thrashed Monaco, ending the Ligue 1 champions’ 100% winning start to the season.
The former Manchester City and Liverpool striker netted from the penalty spot after just six minutes and tapped in his second from close range.
In between, Alassane Plea broke clear and slotted in for the home side.
Debutant Ignatius Ganago added a fourth for Nice late on, going round the goalkeeper and tucking in.
Leonardo Jardim’s side lost just three times last season when they romped to the title with 95 points from 38 games, but they were second best throughout against Nice.
Monaco, who had won their opening four matches this season as part of a 16-game Ligue 1 winning streak, begin their Champions League campaign on Wednesday with a trip to Bundesliga side RB Leipzig.
On Friday, Kylian Mbappe scored on his debut for Paris St-Germain, as they thrashed 10-man Metz 5-1 to maintain their 100% winning start to the season.