PSG coach Carlo Ancelotti blamed the pitch and the referee after watching his side suffer a surprise 1-0 loss to Reims on Saturday.
Despite going down to 10 men, the Ligue 1 strugglers still managed to claim all three points thanks to Grzegorz Krychowiak's strike just after the hour mark.
"This match was different from the defeat against Sochaux. Here, there was no attitude problem," Ancelotti said after the match.
"The pitch today was poor.
"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."
Swedish striker Zlatan Ibrahimovic had his opener controversially ruled offside, and Ancelotti was quick to point an accusing finger at referee Philippe Kolt.
He added: "The standards of refereeing are a general problem here. Yesterday, I saw a decision similarly unfavourable to Rennes. The referees in this league need to be more attentive."
Despite slipping to their fifth defeat in Ligue 1, PSG remain three points ahead of second-placed Marseille.