Toulouse have hit form and made light work of Bayonne at home, while Brive defeated Stade Francais.
Wing Teddy Thomas put more pressure on Stade Francais coach Heyneke Meyer as Racing 92 came out on top in the Paris derby.
An early red card was decisive as Bordeaux-Begles suffered their second defeat of the Top 14 season.
Kylan Hamdaoui scored late as Top 14 strugglers Stade Francais edged out Toulon, while Bordeaux-Begles ran riot against Clermont Auvergne.
Leaders Lyon are the only unbeaten side in the Top 14 after they won a top-of-the-table encounter against Bordeaux-Begles.
Jake McIntrye amassed 22 points as Clermont Auvergne defeated Top 14 strugglers Stade Francais, as Bordeaux-Begles drew with Montpellier.
The top two in the Top 14 claimed huge victories to stay unbeaten as both the defending champions and last year's runners-up were beaten.
The second round of Top 14 fixtures saw hard-fought wins for Clermont Auvergne, La Rochelle and Montpellier, among others, on Saturday.
There were shock wins for Bayonne and Bordeaux-Begles as the Top 14 returned for the 2019-20 season on Saturday.
There will be a new Top 14 champion after Castres missed out on a top-six finish with a final-day defeat to Toulon.