Stade Francais went top of the Top 14 table after thrashing Castres 39-16 on Saturday while European champions La Rochelle slumped to another defeat in a disastrous start to their season.
Lucas Peyresblanques and South African centre Jeremy Ward scored two tries apiece and Sekou Macalou and Rory Kockott also crossed at Stade Jean Bouin as the Paris side made it four wins in five games.
They have a four-point lead over Pau, who host Toulouse on Sunday.
La Rochelle lost for the fourth time in their first five games when they were beaten 19-17 away at Oyonnax.
Irish international wing Darren Sweetnam scored Oyonnax’s only try of the game and Argentinian Domingo Miotti’s boot did the rest, with a conversion and four penalties.
Thierry Paiva’s converted try in the 84th minute came too late for La Rochelle after Joel Sclavi had also crossed.
La Rochelle, European champions for the past two seasons, have seven points and sit in 12th place.
Coach Ronan O’Gara said: “Rugby’s a combat sport, especially when you go to Oyonnax.
“We were aggressive, but we lacked precision all afternoon.”
O’Gara said the team needed a change in fortunes.
“I can’t deflect the responsibility onto the players because above all it’s mine,” the Irishman said.
“We need to bounce back quickly. We’re capable of it. Something has to change rapidly, and I hope it’s not the coach.”
In other games, Clermont were convincing 46-14 winners against Bayonne to move onto 14 points.
Racing 92 face Lyon later on Saturday.
