Montpellier provided the shock of the Top 14 weekend in France, winning in Perpignan while Toulouse cruised past Stade Français.
It was a round of upsets after Toulon lost their second straight home game to Racing-Métro on Friday before Biarritz crashed to newly-promoted Agen.
Elsewhere, La Rochelle got their second win in the top flight with victory over Bourgoin, defending champions Clermont smashed Brive and Bayonne stumbled in Castres.
In the gala match of the day, Toulouse came from behind at half time to cruise past Stade Français.
Agen 28-23 Biarritz
La Rochelle 20-12 Bourgoin
Perpignan 6-16 Montpellier
Clermont 33-9 Brive
Castres 25-16 Bayonne
Toulouse 34 -16 Stade Français.
Friday: Toulon 31 - 36 Racing-Métro
1 Toulouse 10
2 Clermont 10
3 Stade Français 9
4 Bayonne 9
5 Montpellier 9
6 Castres 9
7 La Rochelle 8
8 Racing Metro 8
9 Toulon 6
10 Biarritz 5
11 Brive 5
12 Perpignan 4
13 Agen 4
14 Bourgoin 0
Stade Toulousain 34-16 Stade Français
Stadium de Toulouse
Some had feared that a below-strength Stade Français side would dampen the atmosphere in the Clasico, but when Florian Fritz was sent to the bin after just three minutes for throwing the first punch, it was clear that there was still plenty of passion in the biggest game in French rugby.
In total five yellow cards were dished out (three to the Parisians) in an electrifying encounter.
Stade Français led 16-11 at the break thanks to a try (40th min), three penalties and a conversion from Argentine centre Martin Rodriguez.
Hooker William Servat had barged his way over to score the game's first try for Toulouse, but the hosts were lacking a specialist place-kicker.
Yannick Jauzion, who started at fly-half for Toulouse, finished the first half in the bin for a high tackle.
The complexion of the game changed when Nicolas Bezy came on to take over the pivot berth for the Toulousains in the second period with Jauzion shifting to centre.
It was one-way traffic in the second half as Toulouse scored 23 unanswered points including tries for speedsters Maxime Medard and Vincent Clerc.
In the end it was the Parisian visitors' poor discipline that cost them. They played for half-an-hour with fourteen men on the field and they conceded nearly twenty penalties - suicide against the European champions.
USA Perpignan 6-16 Montpellier HR
Stade Aimé Giral, Perpignan
Montpellier won for the first time ever in Perpignan thanks largely to the domination of their pack - a rare sight for any visiting team at Aimé Giral.
The hosts led 6-3 at half time after their latest fly-half Kevin Boulogne knocked over two penalties. But the Catalans were struggling with a chaotic line-out as hooker Maxime Delonca failed to cope under the pressure of his first start in the first team.
With the wind at his back, Montpellier full-back Benjamin Thiéry slotted over a drop soon after the restart to level the scores.
Centre Martin Bustos Moyana put the visitors ahead with his second penalty before France fly-half François Trinh-Duc scored the game's only try in the 73rd minute to seal an historic win.
SU Agen 28-23 Biarritz Olympique
Stade Armandie, Agen
Disaster for Biarritz, who conceded their second defeat this season despite outscoring their hosts two tries to one.
Former Biarritz fly-half Valentin Current was the hero of the day for Agen as he scored 23 points for his new club and also provided a brilliant pass to put American wing Kevin Swiryn in for the hosts' try in the 63rd minute.
Agen led 18-3 at the break as Current's boot and a simple but effective gameplan from the home side had their Basque visitors bleeding penalties.
The BO scrum was rewarded with a penalty try and young scrum-half Adrien Ayestaran scored a late consolation try created by Imanol Harinordoquy.
Iain Balshaw played at number ten for the Basques, who were a poor reflection of their usual selves.
Stade Rochelais Atlantique 20-12 CS Bourgoin-Jallieu
Stade Marcel Deflandre, La Rochelle
La Rochelle's strong start to the season continues while Bourgoin are now the only winless team in the competition.
Five penalties from full-back Sebastien Boboul punished the ill-disciplined Bourgoin defence.
La Rochelle captain and scrum-half Benjamin Ferrou provided the only try of the game on the half-hour mark after he burst down the blindside to give Les Maritimes a 14-9 lead at half time.
ASM Clermont Auvergne 33-9 CA Brive Corrèze
Parc des Sports Marcel Michelin, Clermont Ferrand
Winning by three tries to none hands Clermont a bonus point after their best performance this season.
The defending champs led 13-6 at half time before turning up the pace in the second half with wonderful display of running from their backs.
That said, victory was built on the dominance of the Clermont pack, who paved the way for tries from Julien Malzieu (28th min), Elvis Vermeulen (55th min) and Vincent Debaty (67th min).
Morgan Parra was as deadly as usual from the kicking tee while Brock James knocked over a drop in a convincing win for Les Jaunards
Brive were in the game until Vermeulen's try, but never really looked like troubling the well-organised Clermont defence.
Castres Olympique 25-16 Aviron Bayonnais
Stade Pierre Antoine, Castres
One of only two unbeaten teams at the start of the weekend, Bayonne finally met their match in Castres.
Bayonne will go home with plenty of regrets after leading for most of the game and generally enjoying the upper hand physically.
Castres full-back Romain Teulet was the hero of the day for the hosts, kicking a total of six penalties including one at the death to deny Bayonne a losing bonus point.
Bayonne led 16-9 at half time thanks to a 10th-minute try from flanker Jean-Jo Marmouyet.
The Castres comeback was sparked however by a try from France winger Marc Andreu, who did brilliant to latch onto a kick from centre Sérémaia Bai to score under the posts.
Teulet's conversion leveled the scores and three more penalties from "Robocop" sealed the victory for the hosts.