Top 14 front-runners Lyon won again, while La Rochelle's Arthur Retiere grabbed a hat-trick and Brive left it late.
Stade Francais came into the Clasico sitting bottom of the Top 14, yet they pulled off a thrilling win in Paris as Toulouse wilted.
Bordeaux-Begles are back at the top of the Top 14 and increased their advantage over Toulon and Toulouse.
Handre Pollard missed some crucial kicks on his Montpellier debut while Top 14 leaders Lyon
Lyon's lead at the Top 14 summit was reduced to just one point as they were comprehensively beaten 33-8 by Montpellier on Saturday.
Toulouse's contrasting home and away form continued as they defeated visitors and 2018-19 Top 14 final opponents Clermont Auvergne.
An early red card was decisive as Bordeaux-Begles suffered their second defeat of the Top 14 season.
It was another game and another win for Lyon in Top 14, where Castres were defeated by Toulouse on Saturday.
Leaders Lyon are the only unbeaten side in the Top 14 after they won a top-of-the-table encounter against Bordeaux-Begles.
Despite seeing their try line breached for the first time this season, Lyon maintained a 100 per cent start to the season in the Top 14.