Relegated Grenoble gave their fans something to cheer about as they humiliated Paris St Germain at the Stade des Alpes.
With PSG looking forward to Saturday's Coupe de France final, they were 2-0 down by half-time thanks to goals from Laurent Batlles and Nicolas Dieuze.
And a miserable day for the capital club was completed after the break when Nassim Akrour and Danijel Ljuboja netted.
It was just a fourth Ligue 1 win of the season for Grenoble, who also hammered Auxerre 5-0 back in February.
PSG boss Antoine Kombouare insisted before the game his side would not be distracted by thoughts of Saturday, but, aside from a Younousse Sankhare shot early which was blocked by Jody Viviani, it was all Grenoble in the first half.
Alaixys Romao won the ball in the air to set up Batlles after 26 minutes, and he struck a fierce shot in off the post past Gregory Coupet from the edge of the area.
Ten minutes later, Ljuboja took the ball past Sammy Traore and crossed toward Batlles, but his header went narrowly wide.
A minute before the break, former PSG man Ljuboja again beat Traore and crossed for the unmarked Dieuze to head home at the far post.
PSG showed briefly after the break, with Mevlut Erding denied by Viviani.
But it was more of the same after 65 minutes as, on the counter-attack, Jean Calve picked out Akrour - again unmarked - and he had time to control the ball and slot home.
Ljuboja got on the scoresheet himself three minutes later.
He too was all alone when Romao dispossessed Peguy Luyindula and picked him out for an easy volley.
Ceara went close late on for PSG, but there was little about their performance to worry Monaco, who drew 1-1 with Le Mans today, ahead of Saturday's game.