MOnaco was awarded a humiliating defeat on Tuesday that nearly ended the club's Champions League campaign when Thierry Henry again failed to win as a coach.
Monaco, semi-finalists in 2017, lost to home side defeats by Club Brugge, who recorded their first victory in four group A games.
Hans Vanaken scored twice for the Belgian side, while Brazilian striker Wesley made it 3-0 and captain Ruud Vormer completed the lead.
Monaco have been without victory in all competitions in their last 15 games when Atletico Madrid beat Borussia Dortmund in their other match.
Henry was hired as a substitute for Leonardo Jardim last month, but has yet to prevail in five games. His team remained in the relegation zone of the French league. The former world champion has his first management job after working as assistant to Belgian coach Roberto Martinez.