Bottom club Le Havre led the league leaders 1-0 at half time on Friday night.
Josh Maja finished from close range after Rayan Fofana set him up, per Sportradar.
PSG started the night first with 17 points. Le Havre were last with just two.
Safonov started in goal. Hakimi captained the side. Digne, Mayulu and Ferran Torres all played.
Dembele, Marquinhos, Kvaratskhelia and Nuno Mendes were all out injured for PSG.
The bottom club came in on four straight defeats, including a 4-3 loss at Marseille.
Vitinha, Fabian Ruiz, Neves and Doue started among the PSG substitutes.
A PSG slip would tighten the race, with Rennes chasing from just behind.
PSG won 1-0 here in February. Barcola scored, and Doue missed a late penalty.
Le Havre 1-0 PSG. Maja's goal is the difference. The second half decides it.
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