Littler displayed poise, confidence and maturity not seen since a certain Michael van Gerwen similarly burst onto the scene as a teenager.
He averaged 105 en route to victory compared to Van Barneveld's 99, as well as hitting nine 180s and finding success with 50 per cent on the doubles.
Warrington's Littler is the youngest-ever player to win a match at the PDC World Championship.
Littler's reward for demolishing the five-time world champion Van Barneveld is a quarter-final match with Northern Ireland's Brendan Dolan, who beat two-time winner Gary Anderson earlier in the evening.
While the age gap is clear on paper - Littler was just two years old when Barney won his first world title - there was little to separate the two in terms of sheer talent and right to be on the stage, with the young Englishman looking every bit the finished article.
Speaking to Sky Sports immediately after his win, Littler still seemed to be taking it all in his stride:
"Unbelievable. I don't know what to say," Littler beamed.
"I went 2-0 up, 3-0 up, then I said to my family, one set away and I'm over the line.
"He (Van Barneveld) said at the end, you can go all the way. I said thank you. He is a true gentleman.
"I do fancy myself, but we have Brendan next."
