Stade Francais could not continue their strong start to the season on Sunday as rivals Racing 92 triumphed in Paris.
Top 14 leaders Clermont Auvergne put some daylight between themselves and second-place Stade Francais on Saturday.
Nemani Nadolo is determined to inspire Montpellier to a first Top 14 title after signing a two-year contract extension.
Toulon will challenge a five-point deduction, which is suspended for three seasons, following comments made by their president.
Montpellier put Toulouse to the sword, Piula Faasalele's dismissal proving to be costly as last year's runners-up scored 10 tries.
Clermont Auvergne remain top of the table, but they suffered a first defeat of the Top 14 campaign at the hands of Bordeaux.
France captain Mathieu Bastareaud must serve a five-week punishment for striking Castres forward Christophe Samson in a Top 14 game.
Centre Gael Fickou has now scored three tries in two games for Stade Francais, the club he joined from Toulouse in May.
Greig Laidlaw kept his cool to maintain Clermont Auvergne's perfect start to the new Top 14 season.
Having retired following last season, Frederic Michalak is back at Lyon as an advisor to president Yann Roubert and manager Pierre Mignoni.
Mathieu Bastareaud was sent off but Toulon fought back to claim their first Top 14 victory of the campaign.
Clermont won an early top-of-the-table clash with Stade Francais, while there were also Top 14 victories for Racing 92, Toulouse and Lyon.
Clermont Auvergne made the most of a chaotic spell in which Racing 92 were reduced to 13 men, triumphing in Top 14 on Sunday.
Castres overturned a 13-point deficit in the second half to beat Lyon in Saturday's Top 14 action.
Montpellier failed to exact revenge on Castres in a repeat of the Top 14 final, losing their first game of the season at Altrad...
Read more
Clermont Auvergne ran hot at the start of the new Top 14 season as the two promoted sides came up short in their opening...
Read more