Who do these 17-year-old's think they are, eh?
Making a mockery of seasoned professionals for 90 minutes? Marseille turning in their own third? Taking to the European scene like it's a Power League five-a-side? The bloody cheek of them.
On a night where Barcelona churned out, arguably, their most impressive performance of the Ronald Koeman era when you take into account the level of opposition - even if Andrea Pirlo's Juventus aren't very good - it was one of these fearless teenage rascals who stole the show.
Pedro González López, known simply as Pedri, had absolutely no right to do what he did to the well-respected Juan Cuadrado on Wednesday night. He had no right to spin past Adrien Rabiot akin to an on-song Zinedine Zidane or perform in a Champions League contest like he was playing in a caged astroturfed arena with a bunch of pals.
Donning the low-sock swagger which further emphasised his supreme confidence, the 17-year-old was deployed out on the left in Koeman's 4-2-3-1 but frequently took up smart positions in the half-space to facilitate Jordi Alba's advancement down his flank and aid combination play with Lionel Messi & Co infield.
When he opted to hold the width, it was often Cuadrado who succumbed to sequences of majestic innovation. A drop of the shoulder here, his own take on the Berba spin there; the seasoned Colombian was simply befuddled by the Spaniard's cheekiness.
""Pedri? When there is talent, age doesn't matter." "- Frenkie De Jong speaking post-match
Pedri's incredible technique when attempting to retain possession in tight spaces is similar to Paulo Dybala's, while his style and skill set has already drawn inevitable Andres Iniesta comparisons.
Admittedly, the way the Spaniard functioned and manoeuvred in a wide left position on Wednesday night was perhaps inspired by the man who he once described as his "biggest reference" and who was often utilised on the left flank during the formative period of Pep Guardiola's reign in Catalonia.
What makes Pedri's Juve showcase all the more impressive, however, is that it arrived merely days after a disappointing outing in the Clasico.
Barcelona were well-beaten by their fierce rivals, with Real Madrid's imperious and harmonious midfield three spearheading their 3-1 victory.
The 17-year-old, though, appeared almost overwhelmed by the occasion. He was frequently caught out defensively, through either poor positioning or improper technique, while Real's vertical compactness and ruggedness made sure of his anonymity in the attacking phase. Pedri had just two touches in Los Blancos' box before he made way late on in the second period.
'Anonymous', however, would be the last word to describe the Spaniard's showing at the Allianz Stadium, as he also impressed from a defensive perspective. Pedri's four combined tackles and interceptions were only bested by the superb Clement Lenglet and typically industrious Sergi Roberto, while his contribution to the visitors' press was notable as Barcelona shunned the hosts for the most part.
Marca's labelling of €5m Pedri as Barça's "Signing of the Decade" in the wake of the Juve victory tells you all you need to know about the Spaniard's overwhelming genius in Turin.
Like fellow 17-year-old Ansu Fati, Pedri appears to boast more than mere talent - which stands him in good stead in regards to fulfilling his potential.
The Spaniard's understanding of his teammates' movement, his own crafty positioning and capacity to fulfil a specific tactical function suggest Barcelona have another impressively intelligent youngster on their books whose skill set lies deeper than technical brilliance.
Denoted as 'scandalously good' by former coach Pepe Mel at Las Palmas, where he notched ten goal contributions in the second tier last term, Pedri's swiftly come to epitomise Barça's evolution under Koeman.
No longer are they a side that merely monopolise possession and play in front of the opposition, they're now an outfit who can attack through direct dribblers in the ilk of Pedri, Messi, Fati, Ousmane Dembele and Francisco Trincao, while also offering significantly more thrust at transitions.
While Fati has rightly been tagged the prime protagonist of the post-Bartomeu era in Catalonia, Pedri's performance on Wednesday night alone was enough to suggest the Spaniard can play more than a mere supporting role.
He, too, should be the poster-boy for an exciting new-look Barcelona.