Grzegorz Krychowiak's strike was enough to give the home side a surprise win at Stade de Reims this evening, and Ancelotti has said that the general refereeing standard is not up to the level required.
"The standards of refereeing are a general problem here. Yesterday I saw a decision similarly unfavourable to Rennes," Ancelotti told reporters after the game.
"The referees in this league need to be more attentive. I can't be angry. It was a technical problem today, and not one with concentration or attitude.
"The team is doing good work, and we are still at the top. The pitch today was poor."
Despite the defeat, PSG still lead Ligue 1 by three points.