Memphis Depay's last-gasp goal earned Olympique Lyonnais a 2-1 home win against 10-man PSG, cutting the Ligue 1 pacesetter's lead down to eight points Sunday.
Depay fired home four minutes into stoppage time to put Lyon on 48 points from 22 games with PSG, who were without the injured Neymar, on 56 after their second defeat of the season.
Daniel Alves was shown a straight red card in the 57th minute after a rough tackle on Tanguy Ndombele. Layvin Kurzawa had cancelled out Nabil Fekir's early opener.
Monaco are fourth on 46 points after goals by Jorge, Rachid Ghezzal and Rony Lopes gave them a 3-1 home win against 10-man Metz.
In Lyon, PSG were caught cold in the second minute when Fekir opened the scoring with a splendid free kick from 30 metres.
The visitor dominated possession but clearly lacked the speed and craft of Neymar, who missed the game because of a thigh injury.
Kylian Mbappe was taken off on a stretcher after colliding with Lyon goalkeeper Anthony Lopes but PSG's club doctor Eric Rolland said it was "nothing serious".
PSG equalised four minutes into stoppage time as Kurzawa unleashed a brutal volley that went under the bar from Alves' cross.
The Brazilian was then sent off for his tackle on Ndombele and PSG cracked at the last moment when Depay unleashed a powerful shot that went into the top corner.
(Cyprien 22) St-Etienne 0
(Jorge 45+1, Ghezzal 67, Lopes 81) Metz 1
(Fekir 2, Depay 90+4) PSG 1
P W D L GD Pts
22 18 2 2 51 56
22 14 6 2 29 48
22 14 5 3 23 47
22 14 4 4 29 46