Highlights: Stade de Reims 1-0 Paris Saint-Germain
Paris Saint-Germain director Leonardo has conceded his team are not suited to the style of French football.
Leonandro could only watch on as lowly Ligue 1 side Reims pulled off the shock of the round, claiming a 1-0 victory over the big spending PSG.
The result was made even more impressive as Reims was forced to play the better part of the second-half with only ten men after defender Christopher Glombard was shown a second yellow in the 60th minute.
The result leaves PSG vulnerable to second-placed Lyon, who could move on to equal points with the Parisians at the top of the table with victory over Brest on Sunday.
However, former AC Milan coach Leonardo said his side would always find it hard to defeat teams similar to the calibre of Reims.
"If we analyse the situation, we can say that we are not made to play these types of games," Leonardo told Infosport. "We're not made for games like that, we're a team made to play in Europe.
"PSG is for Europe, not for France. The playing conditions worked against us while playing against an ultra-defensive team, as did the circumstance we play every three days."
However, the Brazilian did concede PSG would need to find a way to solve its French failings or suffer the Ligue 1 title being wrested from its control.
"When games are based on a fight, we do not succeed," Leonardo said. "We will have to learn how to face games like these though, as they are common here and this (the match against Reims) will not be the last time."