Manchester City and Guardiola proved old trophy winning habits die hard as they demonstrated their class and power to simply prove too much for Arsenal.
It had been a disappointing spell for City, knocked out of the Champions League by Real Madrid after dropping nine points behind Arsenal in the race for the Premier League title.
Here, however, after a first 45 minutes low on quality, City came out for the second half like men possessed, urged on by the animated Guardiola from the sidelines.
City applied relentless pressure before getting their reward with that O'Reilly double, the youngster showing what he can offer under the watchful gaze of England head coach Thomas Tuchel.
Guardiola's new-look City do not yet have the consistency of his side that won a historic four Premier League titles in succession, but when they get it right they are a match for anyone, as they proved here.
Guardiola, like Arteta, kept faith with his Carabao Cup keeper in James Trafford. Whereas his Arsenal counterpart's decision went wrong, Trafford justified his faith with an outstanding triple save early on that proved crucial.
City were the more aggressive and progressive side, in contrast to Arsenal's conservatism and timidity, to secure a fully merited victory.
And Guardiola's elation was clear to see in that touchline sprint and the manner in which he congratulated his players at the end.
Whether this proves to be a psychological blow in the title race remains to be seen, but City demonstrated they are still a force to be reckoned with and not to be underestimated.
Image source, Getty Images
