Contesting their first Carabao Cup final in eight years, Arsenal came flying out of the blocks early on, with Kai Havertz and Bukayo Saka denied by a superb triple save from James Trafford.
Grateful for that reprieve, City gradually grew into the match, as Antoine Semenyo breezed his way past Piero Hincapie, only for the Ghanaian’s inviting delivery to be marginally too high for Erling Haaland in the box.
Pep Guardiola’s men continued to see plenty of the ball as the first half progressed, but clear-cut chances came at a premium as the Arsenal defence remained typically resolute.
The Cityzens did manage to carve out one opening shortly before the break though, as Haaland directed a close-range header off target after more good work from the lively Semenyo.
City carried their growing momentum into the early stages of the second period, and their pressure nearly paid dividends when Jeremy Doku dispossessed Kepa Arrizabalaga, only for the Gunners goalkeeper to cynically pull back the Belgian and receive a yellow card.
The one-way traffic showed no signs of slowing down, and Guardiola’s side deservedly took the lead on the hour mark, when Rayan Cherki’s cross squirmed through the grasp of Kepa, allowing O’Reilly to nod into an empty net from inside the six-yard box.
Having finally translated their dominance onto the scoreboard, City doubled their lead just four minutes later, with man-of-the-moment O’Reilly getting in front of Saka at the back post to brilliantly head home from Matheus Nunes’ cross.
Desperate for a quick response, Mikel Arteta introduced Noni Madueke and Riccardo Calafiori from the bench, and the latter nearly had an immediate impact, driving a low effort against the outside of the post.
The Gunners continued to search for a route back into the match, but Gabriel’s header looped agonisingly against the bar, as City held firm during the closing stages to see out the victory and claim a ninth Carabao Cup crown.
The victory gives Guardiola his 19th trophy in charge of the Cityzens, while Arsenal’s wait for a first piece of silverware since 2020 goes on, leaving their hopes of a historic quadruple in tatters.
Flashscore Man of the Match: Nico O’Reilly (Manchester City)