Joao Cancelo's first City goal was cancelled out by a Matty Taylor strike early in the second half.
But a double from Raheem Sterling sealed the win, with City's youngsters standing up well to a stern test from the League One side who created plenty of chances as the match went on.
It was immediately obvious this was a game of two contrasting styles: Oxford were looking to go direct and hit their front players as early as possible, while City’s primary concern was dominating possession.
It would be a test, then, of our young centre-back pairing Taylor Harwood-Bellis and Eric Garcia, but the home side’s industrial approach didn’t phase our academy graduates, who were dealing with the high balls superbly.
And after 22 minutes, we were ahead.
Joao Cancelo, marauding down the right, was found by a superb pass from Phil Foden and the Portuguese hit a powerful effort that took a deflection off Elliott Moore and flew past Jordan Archer
His first City goal and what a time to get it.
Raheem Sterling, playing as a False 9, should have doubled our lead but his first-time effort after being put through by Bernardo Silva was miscued wide, and just before the break Riyad Mahrez, twisting and turning inside the box, fired a low shot towards the near post that was palmed away by Archer.
If the first half was somewhat dull, the second half began with a bang.
City were caught cold seconds after the re-start. A quick free kick took City by surprise – but Matty Taylor was alert and he went by Harwood-Bellis before firing past Bravo. Game on.
It didn’t take long for City to regain the lead, though. Angelino, who was given freedom to raid down the left side, produced a perfect ball across the box, which was tapped home by Sterling from three yards out.
Our 100th goal in the EFL Cup this decade and there can have been few more crucial.
Cancelo almost got his second but his effort hit the near post, and Mahrez's effort from distance flew into the famous car park behind the goal.
Oxford themselves had chances, Cancelo making a fine block to deny Tarique Fosu-Henry and Bravo saving superbly from Mark Sykes.
But this was a professional performance from City, who weathered a late storm to move through to the semi-finals.
Man of the Match: Phil Foden
What a talent we are cultivating.
Vision, passing quality and an ability to always find space, he is the prototypical attacking-midfielder.
But it’s perhaps the confidence he exudes that is most promising. He always wants the ball and never goes hiding. And, usually, when he has it something good happens.
He will be a creative force for Manchester City for years to come.
Youth and experience
This was another masterclass selection from Guardiola in the Carabao Cup.
His ability to select a side in this competition that perfectly marries the Club’s most promising youngsters with senior players in need of minutes is unrivalled.
He is a firm believer youngsters needs exposure to “men’s football” if they are to progress and is often sceptical about English football’s youth system. This competition offers him an opportunity to do just that.
Our centre-back pairing was home-grown, Stockport-born Foden was pulling the strings in midfield (his third-consecutive start) and Adrian Bernabe came off the bench for the final 20 minutes.
The cream of the CFA crop know they will get chances in the Carabao Cup and, more often than not, they take them with aplomb.
⚽️ Raheem Sterling has scored 1️⃣8️⃣ goals in all comps this season - more than any other PL player pic.twitter.com/15PiPrAlDt— Sky Sports Statto (@SkySportsStatto) December 18, 2019
This was City’s 13th-consecutive win in the EFL Cup against lower league opposition. Our last defeat to a side outside the Premier League in this competition came back in the 2008-09 season under Mark Hughes when Brighton knocked us out.
In fact, our last EFL Cup defeat of any kind came back in October 2016 against Manchester United. Since then we have gone 14 matches unbeaten and won the trophy twice.
What it means
City are through to the last four of this year’s Carabao Cup where we will face Manchester United over two legs!
Leicester visit the Etihad this weekend for a crucial Premier League game. A win for City in that one would close the gap on second-placed Leicester to a single point.
Guardiola has spoken recently about the need to reel Brendan Rodgers’ side in before we can even think about the possibility of overhauling runaway leaders Liverpool. This weekend, then, is hugely significant.
We then play Wolves at Molineux on December 27, before hosting Sheffield United less than 48 hours later.
It’s a crucial period.