Toulon went down 24-9 at Castres falling to their second straight loss to open the season conceding a bonus-point defeat.
For the first time in a decade, they have opened their season with back-to-back defeats, the last time it happened was in 2005-6 when they won just three games all season.
That led to the arrival of Mourad Boudjellal and given the armada of global superstars on their way, there's no chance of a repeat this season.
However on this occasion they fell off too many tackles, and were outmanoeuvred by Castres half-back pairing Julien Seron and Benjamin Urdapilleta, with the help of a couple of former Toulon players.
In the searing heat, both teams showed ambition early on, holding onto the ball for long periods, but not quite finding a way through.
Toulon took the lead through a penalty from Jonathan Pélissié, but it was quickly cancelled out by Urdapilleta.
While the home side were looking more dangerous, a powerful scrum allowed Toulon to move back in front with a second Pélissié penalty.
However they were regularly penalised at the breakdown, and after one attack deep in the 22, Thibaut Lassalle was sin-binned for his team's collective indiscipline.
Castres took full advantage, kicking to the corner and setting up a rolling maul. Toulon held on initially, but eventually Castres forced their way over, with former Toulon player Rudi Wulf the man to emerge from the pile of bodies. Urdapilleta converted despite the windy conditions.
Toulon almost responded before half-time despite being a man down, when young centre Théo Belan scored what looked to be a comical try. Following an apparent knock-on, everyone stopped playing, and the centre picked up the ball and sprinted over. The TMO was called and after checking every angle, the knock-on was spotted and the try ruled out.
Still, Toulon were doing well despite their numerical disadvantage, and after the break they managed to cut the deficit to a point at 10-9 after camping on the Castres line.
The momentum looked to be swinging the way of the visitors, but it was another former Toulon player who turned the tide. Wulf passed out of the tackle to David Smith, and the winger sprinted deep into the 22. The ball went right and then back left, with Seron flipping a high pass out wide for stand-in skipper Alex Tulou to score. Urdapilleta converted from the touchline to make it 17-9.
Seron then went from provider to scorer two minutes later with a fantastic counter-attacking try. After two turnovers Castres got the ball in midfield. They spread it to Rémy Grosso, who beat two men then produced a sublime flicked pass to Urdapilleta. The Argentina fly-half stepped inside Pélissié before playing the two-on-one perfectly for Seron to score.
On the hour Castres almost had another try from a brilliantly-worked set move off a lineout, but Grosso couldn't find Wulf outside him having gone clean through in midfield.
However they were able to see out the final quarter despite Castres losing skipper Tulou to the sin-bin, with both sides having chances to score tries but unable to find a way through.
The European champions face another tough task next week as they travel to Stade Français, while Castres have a local derby at Toulouse.
Tries: Wulf, Tulou, Seron
Cons: Urdapilleta 3
Yellow Card: Tulou
Pens: Pélissié 3
Yellow Card: Lassalle
Castres: 15 Geoffrey Palis, 14 David Smith, 13 Rudi Wulf, 12 Romain Cabannes, 11 Rémy Grosso, 10 Benjamin Urdapilleta, 9 Julien Seron, 8 Alex Tulou, 7 Ibrahim Diarra, 6 Yannick Caballero, 5 Benjamin Desroches, 4 Christophe Samson, 3 Karena Wihongi, 2 Brice Mach, 1 Antoine Tichit
Replacements: 16 Marc-Antoine Rallier, 17 Yohan Montès, 18 Piula Faaselele, 19 Mathieu Babillot, 20 Antoine Dupont, 21 Julien Dumora, 22 Florian Vialelle, 23 Florian Houerie
Toulon: 15 Lachie Turner, 14 Josua Tuisova, 13 Théo Belan, 12 Maxime Mermoz, 11 Sireli Bobo, 10 Willie du Plessis, 9 Jonathan Pélissié, 8 Charles Ollivon, 7 Steffon Armitage, 6 Juan Smith (c), 5 Romain Taofifenua, 4 Thibaut Lassalle, 3 Matt Stevens, 2 Anthony Etrillard, 1 Xavier Chiocci
Replacements: 16 Jean-Charles Orioli, 17 Florian Fresia, 18 Jocelino Suta, 19 Gerhard Vosloo, 20 Anthony Méric, 21 UJ Seuteni, 22 Julien Caminati, 23 Mohamed Boughanmi
Venue: Stade Pierre Antoine, Castres
Referee: Alexandre Ruiz