The game was billed as a battle of two contrasting styles, but in truth City’s brand of incisive, possession-based football dominated Cardiff’s attempts to take a more direct approach.
The brilliant De Bruyne bossed the game from central midfield, finding space and exploiting it at will with his stunning passing range.
On the rare occasions City lost control of the ball, the irrepressible Belgian was usually on hand to race back and retrieve it.
Ahead of De Bruyne, Sterling, Bernardo Silva and Leroy Sane – until the German’s half-time withdrawal through injury - bamboozled the Bluebirds’ defence with technical excellence, work-rate and movement.
And another great sight for City fans was skipper Vincent Kompany using all his nous and strength to snuff out any home attacks.
City were ahead after just seven minutes thanks to De Bruyne’s audacious free-kick.
It’s a trick he’s used before, against Bournemouth last season – a cheeky rolled free-kick that snuck under the jumping Cardiff wall and into the net.
There was a scare for City when Claudio Bravo grabbed Junior Hoilett’s long-range volley at the second attempt on the goal-line, before Callum Patterson just failed to reach an enticing cross.
City were soon back on top, though, and had Bernardo Silva’s stunning ‘goal’ controversially ruled out, with Leroy Sane adjudged to have been offside and interfering with goalkeeper Neil Etheridge’s line of sight. Bernardo, who had just deposited the ball into the top corner from outside the box, was bemused.
The Blues didn’t let the decision become a distraction and soon doubled the lead. It came via Bernardo’s perfect cross, which Sterling nodded in for his 19th goal of the season.
Just before the break a rapid Sane counter attacked was ended by Joe Bennett’s poor foul, and the German was replaced at the break by Sergio Aguero.
City had a tight grip on the game and barely relented in the second-half.
Hoilett went close with one curling effort, but other than City kept the crowd quiet.
Only a last ditch challenge from Sean Morrison denied Sterling after he had rounded the keeper, while De Bruyne went through is passing repertoire to create yet more chances for Bernardo and Sterling again.
Bennett received a second yellow late on for a foul on substitute Brahim Diaz.
24 years ago City were stung by Cardiff at Ninian Park in the FA Cup. Lightning did not strike twice, and as the Blues march on in all four competitions we may well be witnessing a different kind of history being made.
Matchday App Star man – Kevin De Bruyne
Got the ball rolling with his excellent goal and orchestrated events throughout.
Key moment – De Bruyne goal
The early strike turned what looked like a difficult game on paper into a much more comfortable afternoon.
Boss Guardiola shuffled his defensive pack, bringing Danilo in at left-back along with Kompany, who featured for the first time since 27 December. In goal Bravo started a second consecutive game following his appearance in the League Cup win at Bristol City.
With Aguero on the bench, Bernardo started as the most advanced player in a central position, with Sterling wide right and Sane on the left. Sane’s half-time withdrawal through injury meant Aguero came on at the break.
What it means?
City go into the hat for Monday evening’s draw, which takes place at around 7.20pm
City entertain West Brom at the Etihad Stadium in the Premier League on Wednesday, (8pm KO), ahead of next Saturday’s trip to Burnley (12.30pm KO)