The Côte d'Azur derby saw Monaco, previously unbeaten in Ligue 1, fall to Nice at the Allianz Riviera with a score of 2-1, impacted by Vanderson's red card at the end of the first half while the game was tied.

The Brazilian’s dismissal, due to two yellow cards, dashed the hopes of the Austrian coach Adi Hutter’s team, which had been sitting at the top with six wins and two draws until this ninth matchday, tied with Paris Saint-Germain for the lead. PSG could take sole control if they earn points against Marseille.

Monaco took the lead in the 39th minute with a goal from Swiss forward Breel Embolo, assisted by Maghnes Akliouche. However, in stoppage time, Ivorian Evann Guessand leveled the score after receiving a pass from Tunisian Ali Abdi.

Just before halftime, Vanderson received a red card, leaving Monaco to play the entire second half with ten men. They struggled with the numerical disadvantage, and in the 71st minute, Gaetan Laborde scored the winning goal for Nice. This marked Monaco's first loss of the season, placing them in second. Nice, now in eighth place, found victory again after three consecutive draws.