Error-strewn PSG trailed 3-0 and then recovered to lead 4-3 before conceding an injury-time equalizer to Serhou Guirassy in his second goal of the game.
It was the first time PSG conceded three goals in the first half of a league game since February 2012. PSG next faces Borussia Dortmund, which has netted 24 goals in the past six games, in the Champions League on Tuesday.
PSG had got away with making mistakes in its previous three games, but trailed 3-0 within 40 minutes against a side fighting relegation in 19th place.
“It’s obvious we can’t be happy conceding four