Bruno Genesio's men are in the front of Marseille, who host Montpellier on Sunday, on intention difference however sit 12 factors behind runaway leaders Paris Saint-Germain.
The top two qualify automatically for subsequent season's Champions League organization degree, with the third-located side heading into the qualifying rounds.
Rennes have won six of their remaining seven league games to surge into contention, as Nice have slipped from the top three to 5th area after a negative run of effects.
On Saturday, Benjamin Bourigeaud netted twice in four first-1/2 mins to provide Rennes a -aim half-time lead.
Martin Terrier made it 3-zero before the hour mark.
Rennes held on in spite of a past due Reims rally with desires from Maxime Busi and Jens-Lys Cajuste, who netted a penalty simply three mins after his group-mate Moussa Doumbia had ignored one.
Later on Saturday, PSG go to relegation-threatened Clermont.
