The Blues did the hard work in the opening period, going in at the break three goals to the good against the committed Lancastrians.
Clearly, the Blues want to win this trophy for a third year in succession.
Despite a lively start by the hosts, City gradually took command of the tie.
With Bernardo and Raheem Sterling growing into the game, the first real chance didn’t arrive until the 17th minute when Connor Ripley pushed out a Sterling shot, but the England winger was merely setting his sights.
Two minutes later, City were ahead.
Eric Garcia found Sterling just inside the Preston half, but he spun away from his marker and then headed towards goal.
As the home defence parted, he was finally challenged on the edge of the box, but he feigned a shot, lost his man and then sent a deflected shot over Ripley to the delight of the 6,000 travelling City fans.
Three minutes later and Gabriel Jesus was unlucky to see a goal chalked off for offside, but with no VAR to help, the decision stood.
As the half wore on, so City began slicing the home defence to shreds with incisive passing and movement that it became inevitable the lead would increase sooner rather than later.
On 35 minutes, the second goal finally arrived with Sterling’s clever pass expertly driven through Ripley’s legs by the impressive Gabriel Jesus.
And seven minutes after that, the game was effectively over as Sterling found David Silva and the captain’s cross struck the lunging boot of Ryan Ledson and past Ripley for the third of the evening.
The second half was less frantic, with the Blues never likely to lose their sizeable lead and Preston determined to prevent a demoralising thrashing.
The hosts almost pulled one back but Garcia’s late challenge saw the Preston effort strike the post, and midway through the half, Phil Foden smacked the crossbar with a fierce effort.
Jesus went close several times in the closing minutes, but a heavier loss would have been harsh on a hard-working Preston side.
Taylor Harwood- Bellis was calm and confident on his first team debut and his performance will have delighted Pep Guardiola who rates the teenager highly.
Tall and powerful for a 17-year-old, he will become physically stronger in the next couple of years and looks an exciting prospect.
His central defensive partner Eric Garcia continues to impress every time he plays.
At 18, he is an outstanding talent who belies his age and experience at this level and almost scored his first senior goal as he slid David Silva’s cross just past the far post.
Both youngsters will get better and better.
And while we’re on our teen stars, Foden gave a typically busy, creative display that deserved a goal and Adrian Bernabe enjoyed a pleasing cameo and was close to assisting a Gabriel Jesus goal towards the end of the game.
Star man: Raheem Sterling
Involved in all three goals and a threat throughout.
What it means…
The Blues move into the last 16 of the competition and we will learn our opponents after tomorrow’s round of Carabao Cup fixtures.
City travel to Goodison Park for a tricky looking Premier League clash with Everton (5.30pm kick-off).