A magnificent seven-try display from Montpellier earned a resounding 51-10 success over Grenoble and put five points between themselves and third-placed Toulon in Top 14.
The home side led 25-10 at the break thanks to scores from Marvin O'Connor, Davit Kubriashvili and Kelian Galletier.
And further tries arrived in the second period through Bismarck du Plessis, Francois Steyn, Timoci Nagusa and Jacques du Plessis as Montpellier romped to a bonus-point win.
With the top two at the end of the season earning places in the semi-finals, the victory handed Montpellier a significant lead over Toulon, who lost 12-10 at home to Toulouse.
Two penalties each from Sebastien Bezy and Florian Fritz secured the win for the visitors, who are fifth.
At the wrong end of the table, there was a rare win for bottom club Agen, who ended a run of six successive defeats with a comprehensive 37-19 beating of Brive.
Unfortunately, it was not enough to lift Agen off the foot as 13th-placed Oyonnax edged a 17-16 home success over La Rochelle.
Elsewhere, Castres thumped Pau 37-6 and Bordeaux Begles overcame struggling Stade Francais 35-25.