Bordeaux went into their final-day clash with relegation-battling Rodez on June 2 needing to win by more than four goals to pip Metz to the second and final promotion spot in the table behind champions Le Havre.
Les Girondins went 1-0 down inside the first half thanks to a goal from Lucas Buades, who was celebrating with his teammates as a Bordeaux supporter came onto the field to confront him.
The fan disgracefully shoved Buades to the ground, and the referee immediately abandoned the game due to the severity of the situation, leaving Metz and Bordeaux's promotion prospects in limbo.
However, rather than restarting the match, the LFP Disciplinary Committee has punished Bordeaux with a defeat, meaning that they stay in Ligue 2 as Metz return to the top tier.
The decision also has major implications at the other end of the table, as three points for Rodez lifts them out of the relegation zone above Annecy, who have been relegated to the Championnat National 1.
Bordeaux - who have also been docked a point for the start of the 2023-24 season - have confirmed that they will appeal the decision to the French National Olympic and Sports Committee.