Lyon scored all five tries in the second half in a rout of Stade Francais, while Racing 92 claimed their fourth consecutive win.
Clermont Auvergne could only draw with lowly Grenoble and Toulouse took advantage by putting Bordeaux-Begles to the sword in the Top 14.
Three-time European champions Toulon have been struggling in the Top 14 and lost to La Rochelle on Sunday.
Clermont still lead the way in Top 14, but Stade Francais remain on their heels after a late win over Montpellier.
Jerome Kaino will not be available until December after the Toulouse forward failed with an appeal against his five-match ban.
Felix Lambey and Yoann Huget have been called up to the France squad as replacements for injured duo Bernard Le Roux and Wesley Fofana.
The five point-penalty issued to Toulon has been upheld, but following an appeal it will only be suspended for one season.
Julien Arias registered the only try of the game while Jules Plisson kicked nine points as Stade Francais won at Castres on Sunday.
Clermont's advantage at the summit of the Top 14 table was reduced to four points after they were beaten at La Rochelle.
Stade Francais could not continue their strong start to the season on Sunday as rivals Racing 92 triumphed in Paris.
Top 14 leaders Clermont Auvergne put some daylight between themselves and second-place Stade Francais on Saturday.
Nemani Nadolo is determined to inspire Montpellier to a first Top 14 title after signing a two-year contract extension.
Toulon will challenge a five-point deduction, which is suspended for three seasons, following comments made by their president.
Montpellier put Toulouse to the sword, Piula Faasalele's dismissal proving to be costly as last year's runners-up scored 10 tries.
Clermont Auvergne remain top of the table, but they suffered a first defeat of the Top 14 campaign at the hands of Bordeaux.
France captain Mathieu Bastareaud must serve a five-week punishment for striking Castres forward Christophe Samson in a Top 14 game.