Second-placed Montpellier have a mathematical chance to overtake their French rivals when they host them in the sixth and final pool round next weekend, but it would take a miracle for them to deny Toulon a likely home draw.
Wilkinson's previous two forays into the last eight of Europe's top club tournament have both ended in failure – with Newcastle against Stade Francais in 2005 and Toulon against Perpignan in Barcelona in 2011 – and he issued a warning to his team-mates after they had conceded three tries in the final 14 minutes to the Blues.
"The end of the game was disappointing. It doesn't matter if you're a little bit ahead or in a tight game," said Wilkinson, who was captain for the day. "We let a few tackles go, we let them come through the line and, ultimately, they scored a few good tries. It's not the way we want to finish any game.
"Cardiff started very well and we got caught a little bit cold with the try at the start. We picked up the pace, stuck together as a team and we built momentum.
"We've got to congratulate ourselves for winning against a good team and getting to this stage but there's work to do – this tournament is only going to get harder. I've seen this game for 16 years and I know the guys here are as good as any team I have played with."
It was a fifth successive defeat for the Blues, who were quarter-finalists last year, and they will end with a home clash against fellow strugglers Sale next weekend to try to salvage something from this season's campaign.
They were severely disrupted coming into the game, losing Wales lock Bradley Davies with an ankle injury that will require surgery this week, centre Gavin Evans with a back spasm just before the game and utility back Jason Tovey.
"We expected a tough, open game and we knew the conditions would be perfect for fast, flowing rugby," said Blues head coach Phil Davies. "That's exactly what happened. We coped well at times but, on other occasions, it was just too much pressure for us and that's when Toulon scored. But you have to give some credit to our players for getting four tries. That bonus point out here, and from such a young team, was very satisfying
"The average age of our squad is 23. We have a lot of young players, but also strong characters. We want to finish the competition on a high note at home in round six and that will be our only focus over the next week."
The Blues surged into an 8-0 lead thanks to Leigh Halfpenny's early try. But Toulon fought back and ran riot with seven tries through Rudi Wulf, Xavier Chiocci, Jean-Charles Orioli, Maxi Mermoz, Alexis Palisson, Mathieu Bastareaud and Florian Fresia.
To their credit the Blues continued to battle and a break from Williams laid the platform for Cuthbert to squeeze over in the corner. And they continued their late rally with further tries from Hewitt and Halfpenny to claim a bonus point of their own.
Scorers – Toulon: Wulf, Chiocci, Orioli, Mermoz, Palisson, Bastareaud, Fresia tries; Wilkinson 4 cons, Giteau con. Cardiff Blues: Halfpenny 2 tries, con, pen; Cuthbert, Hewitt tries.
Toulon: D Armitage; R Wulf, M Bastareaud, M Mermoz, A Palisson (D Smith 71); J Wilkinson (M Giteau 60), F Michalak (N Durand 56); X Chiocci, JC Orioli (S Bruno 56), C Hayman; J Suta (S Shaw 56), N Kennedy; P Gunther, S Armitage, C Masoe (J van Niekerk 60).
Cardiff Blues: L Halfpenny; A Cuthbert, O Williams, J Roberts (D Hewitt 72), H Robinson; R Patchell (C Sweeney 54), L Jones (G Davies 75); S Hobbs (N Trevett 74), R Williams (K Dacey 62), B Bourrust (S Andrews 45); J Down, L Reed (M Cook 60); J Navidi (L Hamilton 74), S Warburton, R Copeland.
Referee: JP Doyle (England)