Gabriel Jesus scored Arsenal’s first goal in 274 days, sending them to the quarterfinals.
But the Brazilian was eclipsed by the Gunners’ youthful prodigy and budding Carabao Cup star, Ethan Nwaneri.
After scoring two points against Bolton in round three, the 17-year-old showed his talent again by curling home a first-half beauty here.
He came perilously close to adding a few more, but departed the field to a standing ovation from the visiting fans just before the game concluded.
Even if Mikel Arteta might not give this tournament top priority, fans will still want to make it all the way so they can see more of Nwaneri.
The only drawback to the Emirates manager’s incredibly fulfilling evening was that his team did not score more goals.
Despite winning just three of their last twelve games, Preston has been hard to beat since Paul Heckingbottom took over as manager early in the season.
Ethan Nwaneri was the star as Arsenal beat PrestonCredit: AFP
The 17-year-old scored a screamer in the first halfCredit: PA
Gabriel Jesus ended a 25-game goal drought
They have also performed well in this competition, eliminating Championship heavyweights Sunderland and then defeating Fulham in a thrilling penalty shootout to win the Premier League.
However, Arteta’s team, which made eight changes from the squad that drew with Liverpool on Sunday, was too strong for them.
When Nwaneri, who was making just his second start, squandered a good early opportunity, the Gunners seized the lead right away.
The best the home team could manage was a nod from Liam Lindsay over a cross from Sam Greenwood at the other end.
Halfway through the first half, Gabriel Martinelli hit a free-kick from the left, which Jakub Kiwior knocked back into danger.
Jesus, hidden at the near post, volleyed it past Freddie Woodman in a split second.
Kai Havertz scored with a bullet header after coming off the bench in the second halfCredit: Getty
On his debut for Arsenal, Tommy Setford maintained a clean sheet.
It was long delayed, since the Brazilian’s last goal came in the late January victory over Nottingham Forest.
He sent up Nwaneri for the second goal nine minutes later, and the former Manchester City player needed the confidence boost.
To be fair, though, the boy was the center of attention because he managed it beautifully and created a masterpiece by curling up from the edge of the box.
Woodman never moved since he’s been here long enough to know that you don’t preserve those.
Arteta claimed that “the boy is ready” after Nwaneri scored two goals against Bolton in the previous round, and that few would challenge him moving forward.
As the youngest player in history, one can only presume that these are the first of many goals he will score in his first two starts for Arsenal.
If North End had thought the visitors would settle down after the break, they were disappointed.
Nwaneri, an Arsenal teen sensation, made an impression.
Arteta clearly believed there were still goals to be scored, which is why he substituted Mikel Merino and Kai Havertz at halftime.
And just before the hour, Kiwior’s cross was headed in by the German to end the game.
It was a question of how many goals were permitted as Woodman made a triple save to keep them at bay and two goals were also disallowed.
Meanwhile, Nwaneri made another bold but successful attempt.
Given that the boy had made life difficult for North End, it could have been appropriate for another child, Ayden Heaven, to take his place ten minutes later.