Bradford stay top of the engage Super League table despite the shock result, but the loss of two points may knock the out of their stride; the Catalans move away from the bottom four teams into eighth.
Casey McGuire and Stacey Jones were outstanding for the Dragons in what may be their best performance in Super League to date, and it was Bosc who opened the scoring with a try after just five minutes.
A flash in the pan this try was not, and nearly twenty minutes later Bosc grabbed his second, this time converting to give the Catalans a 10-0 lead.
The Bulls fought their way back into the game however, a Paul Deacon try and goal reducing the arrears, and a James Evans touchdown on the stroke of half time ensuring the two sides were level at the interval.
Bosc added another goal after 58 minutes, and Jason Crocker potted a drop goal to edge the Catalans even further into the front.
Bradford fought back in the final ten minutes, tries from Michael Platt and James Evans, both converted by Deacon, reducing the gap to a single point and giving the home support hope of stealing the win.
But a John Wilson try right on full time followed by another conversion from Bosc settled the game in the Dragons’ favour, and set the seal on a memorable win in the French club’s history.