MATCH REPORT: ARSENAL 0 CHELSEA 2
Our Spanish right-back struck his first Chelsea goal before the interval, capitalising on a short Carl Jenkinson back-pass to volley home from inside the box. That means we have had three new goalscorers in the space of 10 days, Azpilicueta joining Andre Schurrle and Samuel Eto'o in notching their first for the club.
The lead was doubled three-quarters of the way through the match via the right boot of Mata, whose sweetly-struck shot whistled past Lukasz Fabianski for his first goal of the season.
In the end, it was a fairly comfortable victory for the much-changed Blues, with our opponents offering little threat going forward. It was in this competition that Mourinho lifted his first trophy as Chelsea boss, and tonight's victory means we are still on course to emulate that feat nine years later.
As promised, Jose Mourinho made wholesale changes to the Chelsea team, with only Gary Cahill retaining his place from the side that beat Manchester City a little over 48 hours ago. That meant a second Chelsea start for Mark Schwarzer between the sticks, with Cahill joined by Azpilicueta, David Luiz and Ryan Bertrand at the back. John Mikel Obi and skipper Michael Essien gave an African flavour to the central midfield positions, while Eto'o was chosen to lead the line ahead of an attacking trio of Mata, Willian and Kevin De Bruyne.
Arsene Wenger made eight changes from his side's win at Crystal Palace on Saturday, but it was still a strong-looking team with Laurent Koscielny, Jack Wilshere, Aaron Ramsey and Santi Cazorla all selected.
Chelsea earned two corners inside the opening couple of minutes but offered no threat from them, while a David Luiz flick over the Gunners' backline proved just too long for Bertrand.
Nicklas Bendtner had a shot blocked at the other end but a scrappy opening saw much of the play interchanged between the two sides in midfield. It took until the 18th minute for the game's first save from either keeper, but De Bruyne's shot, swung in from the left, was straight at Fabianski. Not long after, Eto'o flicked well wide with his back to goal.
There was a moment of real danger for Chelsea when Ryo Miyaichi beat Schwarzer to the ball but first Cahill, and then the offside flag, rendered what had initially looked a problematic situation academic.
Chelsea then took the lead via the most unlikely of sources. It all stemmed from an Arsenal corner, with the cleared Chelsea header setting up a quick counter-attack involving Mata and Eto'o. Essien was also on the scene as we pressed the ball high up but Arsenal's retreating players looked to have the situation under control. Like on Sunday, however, an erroneous back-pass swung the pendulum in our favour. Carl Jenkinson's header was short of Fabianski and Azpilicueta, raiding forward, was on hand to expertly volley past the Pole via the inside of the post. What a way for the Spaniard to score his first goal for the club!
Mikel went into referee Phil Dowd's book for trying, but failing, to halt the advancing Wilshere and with the home side looking for an instant response, Nacho Monreal passed up Arsenal's best chance of the opening half moments later. Azpilicueta sold De Bruyne short, but Arsenal's Spanish full-back couldn't match his compatriot's effort, driving just wide of Schwarzer's far post.
Essien, his usual bustling self, should have done better when set up following some intricate Mata approach play, but a disjointed first period finished with both sides perhaps suffering for the multitude of pre-match changes.
Attacking the 9,000 travelling fans massed behind that goal, we were first to threaten. Eto'o stepped inside Koscielny outside the box but the Cameroonian's shot, all of his own making, flashed wide with Fabianski scrambling.
The in-form Ramsey danced his way into the Chelsea box but a Mikel block took the sting and the danger out of his strike, and the same man flashed wide five minutes later. Arsene Wenger threw on summer signing Mesut Ozil after the hour in a bid to inject some quality into his attack that, up to that point, had looked pretty toothless going forward.
Our next attack was anything but, as Juan Mata doubled our advantage. Eto'o helped a Bertrand throw-in towards Willian, who flicked his header back to Mata. The Spaniard, lurking on the edge of the area, took one touch with his left to shift it on to his right. His shot was fierce, blasted beyond Fabianski into the top right-hand corner. Our no.10 couldn't have opened his account for the season in a more spectacular fashion. 2-0 Chelsea, 65 minutes played.
Schwarzer had to be alert to block with his knees from substitute Olivier Giroud, after Wilshere had wriggled his way into the box for the first time in the match, but it was the visitors who went closest to adding the game's third goal. A swift break involving Azpilicueta ended with Essien feeding the recently-introduced Ramires. From a tight angle, our speedy Brazilian lifted his effort over Fabianski. The retreating Koscielny could count himself fortunate to stand on the ball, and not put it into his own net, as it neared his goal-line.
Cazorla drifted into a shooting position as Arsenal sought a late consolation, but, like many of his team-mates' efforts, his shot failed to test Schwarzer.
Ramires almost had the game's final word, his dipping strike just clearing the motionless Fabianski's crossbar. By the time Tomas Kalas was introduced for his Chelsea debut in stoppage time, the Emirates was half-empty, save for the buoyant travelling support, revelling in their team's performance.
This was by no means the most fiercely-contested London derby, but a first goal in Chelsea colours for Azpilicueta and a stunning first of the season for Mata puts us in the hat for the quarter-finals of the Capital One Cup.
Chelsea (4-2-3-1): Schwarzer; Azpilicueta, Cahill, D Luiz, Bertrand; Essien (c), Mikel; De Bruyne (Ramires 68), Mata (Kalas 90+2), Willian; Eto'o (Ba 80).
Unused subs Blackman, Ivanovic, Hazard, Torres.
Scorers Azpilicueta 25, Mata 65
Booked Mikel 28, Essien 74
Arsenal (4-2-3-1): Fabianski; Jenkinson, Koscielny, Vermaelen (c), Monreal; Ramsey (Park 81), Wilshere; Miyaichi (Ozil 63), Rosicky, Cazorla; Bendtner (Giroud 66).
Unused subs Viviano, Sagna, Hayden, Yennaris.
Referee Phil Dowd