PSG defender Marquinhos called on his team-mates to forget Saturday's dismal 3-0 defeat at the hands of Montpellier.
Goals from Paul Lasne, Ellyes Skhiri and Ryad Boudebouz consigned the reigning champions to their third loss of the season as they missed the opportunity to overtake Monaco and Nice at the top of Ligue 1.
And Marquinhos, who was dispossessed on the edge of his own box in the build-up to Montpellier's second goal, was keen to draw a line under the surprise setback at the Stade de la Mosson and move on.
"There are not even words to explain this game and we have to forget it immediately," he told Canal Plus Sport. "We must not make the same mistakes if we want to be champions, but when you take a slap, you learn a lot.
"We must immediately get back to work. The fans will see a different Paris in the next game."
Club president Nasser Al-Khelaifi, meanwhile, was scathing in his assessment of the performance and PSG's mental approach.
"We did not deserve to win that game, that's the truth," he said. "Today we were not in the game, we were not effective. I think we lost the game before we played the game.
"Playing a game before the Champions League is always difficult and there have been many changes in the team, but that's no excuse. It's a shame but we have an important game on Tuesday [against Ludogorets] .
"The most important thing is to look at what has failed today in order to improve and then forget this game."
