Stade Français kicked off their Top 14 campaign in fine style with a big win over Montpellier on Saturday before Jonny Wilkinson kicked Toulon to victory in Perpignan.
Clermont underlined their title credentials with an impressive victory away to Bayonne.
New boys Grenoble casued the first upset of the season when they beat Bordeaux.
Biarritz made light work of newly-promoted Mont-de-Marsan while Racing Metro won on the road in Agen.
In Friday's season opening fixture, defending champions Toulouse came from behind to narrowly beat Castres.
"I am particularly proud of the mental strength of my players," said Toulouse coach Guy Noves.
"Once again when we were in difficulty, and up against it at the end of the match, but we found the resources to get through. It's a win that undoubtedly will be very important later."
Biarritz Olympique 35-10 Stade Montois
Biarritz were the only team to secure a bonus point to go top of the standings.
Damien Traille and Iain Balshaw grabbed tries before the interval with Wenceslas Lauret adding a third in the 65th minute.
Benoit Baby's last-minute try ensured the bonus-point win for Biarritz.
SU Agen 20-24 Racing-Métro 92
Racing win their first game at Stade Armandie since returning to the top flight.
Ross Skeate scored on debut for Agen to help the hosts to a 17-13 half-time lead but two second-half yellow cards cost the hosts dearly.
Stade Français Paris 32-16 Montpellier HR
French international full-back Jerome Porical marked his Stade Francais debut in style by kicking 22 points in Saturday's win over an ill-disciplined Montpellier.
In a match played in 30-degree heat Montpellier struggled without their Argentina stars who are with the Pumas on international duty in South Africa.
They were also reduced to 13 men at one stage when skipper Fulgence Ouedraogo and full-back Jean-Baptiste Peyras were both sin-binned.
The sides were level 9-9 at the interval but Stade grabbed two second half tries through Australian fly-half Paul Warwick and hooker Remi Bonfils.
Union Bordeaux-Bègles 28-29 FC Grenoble
Grenoble scored four vital points in what is set to be a season-long fight to avoid relegation.
The newcomers led 17-0 after 14 minutes but UBB faught back to lead 18-17 at the break.
However, three penalties from new fly-half Valentin Courrent in the last quarter secured first Top 14 win for Grenoble.
Aviron Bayonnais 6-13 ASM Clermont Auvergne
Clermont wing Jean-Marcelin Butttin scored the only try early in the second half of a dull affair in the Basque to give Clermont a winning start to the season.
Bayonne will rue the poor kicking form of fly-half Jacques-Louis Potgeiter, who left a bunch of points by the wayside.
USA Perpignan 15-21 RC Toulon
It wasn't pretty but the Toulon 'army' got their first win of the new season thanks to their dominant pack in an untidy season-opener which saw 29 penalties awarded in a frustrating stop-start encounter.
Anglophone kickers scored all the points but James Hook's five penalties feel short of Jonny Wilkinson's six and a 70th minute match-winning drop gaol.
Hook put USAP 15-12 ahead at half time but Wilko ended the night with a 100 percent record as the visitors defensive wall was immovable.