It was an unusual sight to see José Mourinho dressed down for the occasion. In his electric blue tracksuit and matching zip-up puffa coat, one could be forgiven for wondering if he might have been a little relaxed about a Capital One Cup tie in which he had idly threatened to field his development squad. Not a bit of it.

There was a determination and focus in Chelsea which reflected the seriousness and affection which Mourinho has always shown for this competition. Besides, winning is winning and Chelsea's team, including several who are in the business of proving to their manager that they deserve more game-time in the more glamorous fixtures, understood the message loud and clear.

In a World Cup year particularly the desire to make that step from squad member to one of the chosen few is maddeningly strong. For Juan Mata, David Luiz and Gary Cahill, for instance, convincing Mourinho to trust them for regular Premier and Champions League starts is a mission that cuts to the core. They played with conviction, confidence and power.

With two points separating these two form teams, there was a subtext here: look at the power of the squad, the quality in reserve, the readiness of those who will need counting on. It finished advantage Chelsea.

This was a starting XI from which Cahill was the only survivor from the exhilarating victory against Manchester City on Sunday. Understudies? Hmmm. Hardly. This collection had 669 international caps between them. With the quality on the bench added Chelsea had a Capital One Cup squad which cost more than £250m.

Up against such obvious class and experience, just what Arsenal did not need was a moment of recklessness. Chelsea drew blood, not for the first time this week, thanks to a happy knack for pick-pocketing opponents who are simply not paying attention.

In this evening's performance the role of Matija Nastasic was played by Carl Jenkinson, and Lukasz Fabianski took on the role of Joe Hart. César Azpilicueta emulated Fernando Torres in clinically saying "muchas gracias" to a pair of devastated opponents.

Arsenal were rightly irritated with themselves for handing Chelsea such a generous offering. The mistakes were manifold. It was a corner to the home team. Chelsea were able to break into vast plains of space. The danger still should have been comfortably covered, only for Carl Jenkinson – who may or may not have noticed Jack Wilshere's gesture to leave it – to nod a looping header into no man's land between him and his keeper.

Azpilicueta tucked his gift into the bottom corner, way beyond the reach of the stranded Fabianski. Little wonder he wheeled away in delight, having scored only once in his entire career before. Like many on the night his desire to make an impression was almost tangible.

Arsenal's frustration was enhanced by the fact that the handful of players from their first XI played well enough. There were glimpses from Santi Cazorla, Aaron Ramsey and Jack Wilshere but against a side of Chelsea's collective strength individual moments were not enough.

If a team is only as strong as its weakest links, then the writing was on the wall for Arsenal not only with the opening goal they gave away but also the bluntness at the head of their team. Nicklas Bendtner made his first start for Arsenal at the Emirates Stadium since March 2011. The event was anticipated with a hint of mirth by the Gooner fanzine, which had the Dane mocked up as Jesus with a speech bubble declaring: "Trust in me and I will deliver." In the event it was more second rate than second coming.

Mourinho was able to bring on Demba Ba for the last few minutes, which resonated uncomfortably as it was Chelsea's toying with Arsenal over a loan deal on deadline day that led to Bendtner staying at the club as cover for Olivier Giroud. When Arsène Wenger introduced Park Chu-young, the forgotten South Korean, it was yet another marker of the difference in resources in reserve for Arsenal and Chelsea.

Mesut Özil and Giroud did come on to try to add more class to Arsenal's endeavour but between the two substitutions designed to turn the tide Chelsea sauntered into a grander lead with a sumptuous goal from Mata. Of all the players trying to convince Mourinho of their case, his status on the fringe remains the most enigmatic and mystifying. There are not many clubs in England who would refuse to put a player of his guile and gloss straight into the heart of their very best XI.