Tries from Jamie Roberts, Bradley Davies and Leigh Halfpenny gave Dai Young's squad record a truly memorable victory in front of a partisan crowd at the Stade Veledrome.
Close to 50,000 fans saw the Blues shock Jonny Wilkinson and co with a superb performance that was based on defensive heroics as well as a clinical and inventive display in attack.
The Blues trailed 13-6 at half-time, with Toulon looking in control in the final game of the European club season.
But the Blues never gave up despite being written off by commentators and critics alike and it was they who were celebrating when the final whistle blew on a thrilling encounter.
As well as going someway to making up for the Blues' heartbreaking Heineken Cup semi-final defeat to Leicester Tigers this time last year, the win ends a 15-year drought for Welsh sides in continental competition.
Cardiff, Pontypridd and Caerphilly had all gone close in previous years, but it is the Blues who will be forever remembered as Welsh rugby's European pioneers.
The result also brought a second piece of good news to Welsh rugby, with the Scarlets benefiting from the Blues' breathtaking display.
Nigel Davies' men had missed out on Heineken Cup qualification through the Magners League but will now be back at Europe's top table next season after the Blues secured an extra Welsh place in the competition.