Newly-promoted Bayonne marked their return to the Top 14 with a stunning 28-23 victory over last season's runners-up, Toulon.
The big-spending visitors were never allowed to settle by a committed home side receiving the backing of a raucous and partisan crowd at the atmospheric Stade Jean Dauger.
Bayonne hooker Gregory Arganese and Toulon flanker Charles Ollivon both found the line in the first half and the sides went into the break locked at 13-13.
But Arganese's second five-pointer and a further score from Jean Monribot, along with impressive goal-kicking from both Willie du Plessis and Martin Bustos Moyano, took Vincent Etcheto's men out to a 28-16 lead midway through the second half.
Second-row Romain Taofifenua did cross for the visitors to set up a tense final 10 minutes, but without their Rugby Championship contingent, Toulon were unable to claw their way back.
Following a tough baptism in his first competitive game in charge, new Toulon coach Diego Dominguez will be hoping for better fortune next Saturday when his side return to the south-west to face Pau.
Buoyant Bayonne, meanwhile, have another home game to look forward to, this time against Castres.