Clermont moved ahead of long-time leaders Toulon in France's Top 14 on Saturday with a runaway 37-10 win over Stade Francais at the Stade de France.
The five points they took away from Paris put them on 69 points, two clear of the Mediterranean side, who have a home game against third-placed Toulouse later in the day when a win would see them return to top place.
Clermont opened strongly with a try after just two minutes. Welsh international full-back Lee Byrne bursting through the home defence and feeding French centre and club captain Aurelien Rougerie for a try which Morgan Parra converted.
Two more tries from Canadian lock Jamie Cudmore after 12 minutes and New Zealand winger Sitiveni Sivivatu after 27, both converted by Parra, put the side from Auvergne 24-3 up and firmly in command at half-time.
Despite the absence of several international players, Clermont kept up the pressure in the second half, moving ahead 30-3 with two more Parra penalties before Stade finally dotted down through replacement Martin Rodriguez Gurruchaga
But with four minutes to go, Clermont had the last word and a handy offensive bonus point when powerful Fiji winger Napolioni Nalagi bulldozed his way through the line to score.
The defeat, their first at home this season, all but ends the fading hopes of Stade Francais to grab the sixth and final place in the playoffs which follow the regular season and end in the championship match back at the Stade de France on June 1.