Kingsbarns staked his claim for Classic glory in 2013 with a clear-cut victory in the Racing Post Trophy at Doncaster.
Having only his second career start after easily winning a Navan maiden 17 days earlier, the 15-8 favourite led over a furlong out to give trainer Aidan O'Brien his seventh success in this Group One race.
Van Der Neer stayed on well for second, beaten a length and three-quarters, with Steeler third.
Jockey Joseph O'Brien said: "He relaxed and travelled very well.
"I might have got to the front too soon, but my momentum took me there.
"He was very green, but I think he is going to be a very good horse.
"Soft ground or quick ground, he'll have no problem."
Another Irish challenger, Trading Leather, was first into the lead, but Steeler was soon upsides before taking the advantage.
Kingsbarns then quickened in good style to seal the race, and had enough in hand to hold the late charge on the stands side of Van Der Neer.
Ballydoyle's inmate was roundly cut in the betting as favourite for the 2013 Investec Derby.
Aidan O'Brien said: "We're obviously thrilled.
"When he won his maiden a little under three weeks ago, he'd just arrived and won very nicely.
"After that we were half-thinking of leaving him alone.
"He's a lovely horse and had done great through the year.
"We did one little bit of work with him and it was lovely.
"Then the final exam for the Racing Post Trophy was there.
"He came through it with flying colours."
O'Brien snr added: "We had Camelot last year and then this horse has come along.
"The boys (Coolmore) will sit down and talk over the winter what they want to do with him but he has all the options open to him.
"They made the decision to let him come here and run by himself.
"He'll canter during the winter, we'll train him in the spring, and then they will decide.
"He's a great traveller and has loads of natural speed."