Clermont notched up a crucial bonus-point win over Stade Francais in Paris while Toulon beat Toulouse in Saturday's Top 14 action.
Elsewhere, Bordeaux hammered fellow strugglers Agen 48-17 to swap places in the table, running in six tries at Stade Jacques Chaban-Delmas.
Racing Metro proved to be easy winners over Grenoble in Paris, with Juan Imhoff crossing twice for the game's only five pointers.
Stade Francais 10-37 Clermont
Clermont's victory increased their points tally to 69 and temporarily moved them above Toulon into first place in the league table.
The 2011 champions opened the scoring after just three minutes thanks to a try from captain Aurelien Rougerie, who capitalised on a fine break from Wales full-back Lee Byrne. Jamie Cudmore then increased the lead by powering over the last defender to give Clermont a 17-0 lead after 14 minutes.
Former All Black winger Sitiveni Sivivatu then got in on the action after more good work from Rougerie, with the former France international luring in Francis Fainifo for Sivivatu to finish, leaving Clermont with a healthy 24-3 lead by half-time.
Martin Rodriguez grabbed a score back for the hosts after two penalties from Morgan Parra stretched Clermont's lead, before a brilliant run from Naipolioni Nalaga through three tacklers clinched the crucial bonus point.
Bordeaux 48-17 Agen
A rampant Bordeaux crushed visitors Agen to move above their rivals at the bottom of the Top 14 and into 10th place.
The hosts ran in six tries, including two for hooker Ole Avei, and led comfortably 17-0 at the interval after a fine performance from fly-half Camille Lopez.
Lopez carried on where he left off in the second-half, adding an early drop-goal before Bordeaux ran in two tries in three minutes, including Avei's second.
Ross Skeate grabbed a consolation score for Agen shortly after but from there Bordeaux cantered home, thanks to tries from Rey and Lopez - who finished with 23 points.
Racing Metro 23-3 Grenoble
Racing Metro were comfortable winners in their home fixture against Grenoble, thanks to a brace of tries from Argentinian international Juan Imhoff.
Imhoff struck in the 10th and 43rd minute to give the hosts a comfortable 23-0 lead.
Blair Stewart managed to get Grenoble some points on the board with a penalty in the 47th minute on an afternoon to forget for the visitors, who remain in eighth place.
The victory for Racing secures their spot in sixth as they remain on 54 points with Montpellier, after their seventh consecutive victory.