Castres are lead the way in the Top 14 table as Clermont and Stade Francais both lost on their travels on Wednesday.
Stade continue to struggle away from home as Brive beat Montauban
Castres are the new leaders in France after Clermont and Stade Francais both suffered European hangovers in Top 14 midweek action.
Racing Metro made the most of a fast start to see off Clermont 33-24 in Paris having at one stage held a 27-point lead over the opponents.
With their rivals slipping up on the road, Castres took full advantage with a home win over Stade Francais, who continue to struggle on the road.
In Wednesday's other fixtures, Brive beat Montauban 19-14 while Toulon saw off Montpellier. Six more teams are in action on Thursday night.
Racing Metro 33-24 Clermont
Racing ran in three tries in the space of 13 first-half minutes on their way to an impressive home win over previous leaders Clermont.
Henry Chavancy, Dan Scarborough and Sireli Bobo touched down to help the home side open up a commanding 27-0 lead at half-time.
However Clermont - who will face Leinster in the quarter-finals of the Heineken Cup - staged a tremendous fightback after the break.
Loic Jacquet, Gavin Williams and Anthony Floch all managed tries but it wasn't enough for the visitors, who slip off top spot.
Toulon 31-19 Montpellier
Toulon grabbed a welcome bonus on home soil as they notched four tries in a convincing triumph over Montpellier.
Australian centre Mafileo Kefu ran in the first after five minutes and it took only another four for the hosts to score again - this time through New Zealander Fotunuupule Auelua.
After the early burst the home fans had to wait until after the break for a third try, eventually scored by Scottish full-back Rory Lamont.
A late effort from Olivier Missoup sealed the extra point for Toulon, helping them move into fourth position in the standings.
Castres 32-14 Stade Francais
Stade Francais slipped to eighth in the table after the side from Paris surrendered a 14-9 half-time lead.
They seemed set to put their away woes behind them when centre Geoffrey Messina's try, plus a pair of penalties from Lionel Beauxis and three points from the boot of Ignacio Mieres, put them in control after 40 minutes.
Castres fought back, though, taking advantage of prop Rayno Gerber's sin-binning to score a try through No.8 Chris Masoe.
Romain Tuelet added the conversion before adding three penalties to the trio he kicked before the interval, giving him a personal haul of 27 points.
Brive 19-14 Montauban
A try apiece in the first ten minutes promised much, but matches in Brive are rarely entertaining affairs these days.
Alexis Palisson converted Fabrice Estebanez's try - the week in which latter was called up to the France squad - and kicked four penalties.
Len Olivier replied with two penalties for Montauban, and Cedric Rosalen's late penalty at least snaffled Montauban a bonus point.
