There was always going to be a flashpoint and when it arrived Mikel Arteta’s reaction was both predictable and instant.
So much had been said and written about Pierre Emerick-Aubameyang, the Chelsea striker who this time last year was still wearing Arsenal ’s armband, in the lead up to this London derby that there simply had to be a moment.
And even though the pair did not lock horns directly, the reaction of Arsenal’s head coach on the touchline was impossible to ignore.
For 27 minutes Aubameyang had been anonymous. Then he slid in on Ben White with a challenge that not only left Arteta raging like a madman but endeared him further to his former fans, who produced an impressive cocktail of expletives.
Arsenal’s head coach is earning a reputation for his touchline behaviour. He seems to spend more time outside of his technical area than in it and every 50/50 that goes against his team is treated with grave offence.
The sight of Aubameyang sliding in on White was never going to be accepted quietly. Off Arteta went, at first directing his ire at the assistant referee to his right and then to the fourth official before exchanging undoubtedly explicit views with Graham Potter’s backroom staff.
On the pitch Granit Xhaka, who had hugged Aubameyang pre-match, asked for a red but yellow was unquestionably fair because it did not seem malicious in real time, simply poor timing, and White made a swift recovery having initially writhed around in apparent agony.
Arteta returned to simmering instead of boiling over - further angry exchanges with Chelsea assistant Billy Reid would follow before the break and, in the second half, there was a bizarre moment in which he tangled with Cesar Azpilicueta as the Chelsea captain sought to take a throw in.
Rather than channel his yellow card into a more familiar impact, however, Aubameyang immediately returned to the outer fringes of the game. And from there he remained until being hauled off immediately after Gabriel put the league leaders in front with their second shot on target of an entertaining if not especially high-quality fixture.
For all the talk of settling scores and the well-told tale of “disciplinary breaches” which led to Aubameyang's departure from the Emirates last season, there is a far bigger, likely incurable, issue at play. At 33, a forward whose supreme quality was a blistering turn of pace is evidently over the peak and beginning his descent.
And more worryingly for Chelsea this is a theme that goes through the spine of the squad inherited by Graham Potter. The combined age of Chelsea’s starting 11 here was 310, with five of those players over the age of 30. By contrast Arsenal’s team totalled 268 with only Granit Xhaka into his fourth decade.
It was a shock, then, to learn that the visitors were sharper and faster from the outset - even if they did not register a shot on target until the hour mark.
Chelsea’s midfield, comprised of Jorginho and Ruben Loftus-Cheek, were too often bypassed by Arsenal’s movement and White’s commitment to attack offered an additional dimension that left Marc Cucurella far from comfortable at left back.
It was only profligacy that denied Arsenal the lead, with Gabriel Jesus contriving to send a diving header wide after Gabriel Martinelli produced a delicious cross from the left in the 29th minute.
Chelsea were almost entirely reliant on counterattacks but even the best of those culminated in slack final balls from Havertz, the least muted of a front quartet in which Mason Mount and Raheem Sterling barely had a touch.
The home side did at least begin the second half with some display of intent but few could dispute that the opening goal, coming just as Armando Broja was being readied to replace Aubameyang, was deserved - irrespective of it being a scramble in which Chelsea’s defence lacked decisiveness.
From there Bukayo Saka and Martin Odegaard sent decent efforts over but the grim reality for Chelsea is that they never came close to levelling to leave them seventh in table and with mounting problems.
In the medium-term Chelsea’s squad needs significant surgery, despite spending more than £200m in the summer. Arsenal’s core, on the other hand, looks capable of developing together for the next five years - a fascinating prospect considering they are one win away from entering the World Cup break on top of the table.
