Gabriel Jesus, Riyad Mahrez, Phil Foden and Aymeric Laporte all notched on a comfortable night for City - who still haven’t lost a game in England’s secondary club competition since 2016 - and the returning Gabriel Martinelli suffered another injury blow on his first start in nine months as the pressure continued to mount on under-fire Gunners boss Arteta.
Arsenal - who made eight changes from Saturday’s Premier League defeat by Everton and remained without captain Pierre-Emerick Aubameyang due to a calf injury - started the contest in the worst possible fashion, with the fit-again Jesus slipping into the gap between Shkodran Mustafi and Gabriel Magalhaes - back from suspension - to head in Oleksandr Zinchenko’s decent cross from the byline with Alex Runarsson leaving himself stranded.
Skipper Fernandinho then went close with a fizzing low effort as the crisis-stricken Gunners already began to look completely shorn of confidence.
City were dominating possession as Runarsson - offered a rare chance to impress in place of usual no1 Bernd Leno - looked totally unconvincing with the ball at his feet, though Lacazette headed wide after good industry from Joe Willock before Mahrez saw a shot deflected behind by Mohamed Elneny.
Elneny and Shkodran Mustafi both went into the book for challenges on the impressive Jesus after Laporte had sent his own header just wide, while Dani Ceballos tumbled theatrically to the ground after being caught with a hand to the face by Fernandinho as the pair jostled for position at a City corner.
Mahrez curled a free-kick into the wall and Runarsson inexplicably then came racing out of his area for no good reason, though did temporarily redeem himself later in the half with a fine close-range stop to thwart Jesus after terrific build-up play also involving Mahrez and the silky Foden.
With his energy and commitment, Martinelli was comfortably Arsenal’s best player in the first half and it was his cross from the byline that presented the ball for Lacazette to expertly head home after escaping the attentions of Laporte.
However, the Brazilian suffered what appeared to be a right ankle injury after being caught during a challenge from City’s back-up goalkeeper Zack Steffen, who had come charging out of the box to stop Martinelli collecting a searching through ball from Willock.
Martinelli looked in considerable pain as he received treatment with his shirt pulled over his face and limped off gingerly, though did make it to half-time and even began the second 45 before going down again two minutes after the restart and being replaced by Nicolas Pepe.
Shortly after that blow Arsenal found themselves behind again, with the hugely unconvincing Runarsson allowing Mahrez’s free-kick to squirm through his fingers and in after the Algerian was brought down by Gabriel and Elneny.
Things got worse for the Gunners just before the hour mark when a swift City counter-attack ended with Foden showing tremendous poise and a deft touch to lift Fernandinho’s through ball over the on-rushing Runarsson.
To add insult to injury for Arteta’s men, replays showed that Foden was offside when the pass was struck. However, with no VAR at this stage of the Carabao Cup, the goal stood.
Foden later turned provider, producing a tremendous cross after a short corner that was nodded in easily by Laporte.
City’s bid for a fourth successive Carabao Cup triumph remains firmly on track as they join Brentford in the last four following an incredible 18th successive win in the competition, while Arsenal are still searching for answers ahead of a tough Boxing Day London derby against Chelsea.