PSG came from 2-0 down inside eleven minutes to win 4-3 against Valenciennes and reclaim top spot of the Ligue 1 table with Montpellier to play on Monday.
Carlo Ancelotti's richly-assembled squad hung on for an invaluable win, to go ahead of Montpellier on goals scored only, after they had been forced to battle back from 2-0 down.
Vincent Aboubakar and Remi Gomis stunned the capital club inside the opening 11 minutes but PSG's reply was even more impressive as they roared into a 3-2 lead before half-time.
Nene, Maxwell and Blaise Matuidi grabbed the goals and a defining win looked assured when Jeremy Menez added a fourth on 58 minutes.
But there was further drama as Aboubakar grabbed his second with 10 minutes left, but PSG just about managed to cling on for a win that puts the pressure back on Montpellier.
Lyon's hopes of a top-three finish and Champions League football took a huge hit with a 1-1 draw at home to relegation battlers Brest.
Yoann Gourcuff gave Les Gones a first-half lead but Brest snatched a point through Gregory Lorenzi's equaliser.
The result leaves Lyon eight points behind third-placed Lille, who will assure themselves of a top-three finish if they beat Caen on Monday.
Ajaccio were plunged into relegation danger as they slipped to a 2-1 defeat at Evian and saw Carl Medjani red-carded late on.
The visitors took the lead through Benjamin Andre, but Cedric Barbosa immediately equalised and Daniel Wass' second-half free-kick earned the three points for Evian, who are set for a top-half finish in their first season following promotion.
Ajaccio, by contrast, are just three points outside the relegation zone having played a game more than all three teams in the bottom three, and will have to contend with the suspension of Medjani after his frustrated two-footed lunge at Wass.