Thomas Tuchel said his Paris Saint-Germain side lacked "hunger" after they were shocked by Guingamp in the quarter-finals of the Coupe de la Ligue on Wednesday.
PSG conceded three penalties in the game, two of which were converted as they fell to their first domestic loss of the season.
Neymar put the hosts 1-0 up at the Parc des Princes just after the hour. But Yeni Ngbakoto equalised from the spot in the 81st minute before Marcus Thuram, who had earlier missed a spot-kick, netted the winner from 12 yards deep into stoppage time.
Tuchel believes his side, who are 13 points clear at the top of Ligue 1, can learn from the defeat, per Canal+ (h/t Goal's Matt Dorman):
"I do not know if it's deserved; we had a lot of chances.