Long-time friends Mikel Arteta and Xabi Alonso are at very different stages of their managerial careers in the English top flight.
The former is now somewhere close to having the squad depth he has long desired as well as the right mix of characters within the dressing room, whilst the latter could be said to be merely the latest cannon fodder in West London after yet another whirlwind summer transfer window.
Chelsea's lightning-fast start
However, it was the Blues that started this match like a steam train, and were ahead within a minute and 20 seconds of the kick-off, thanks to Morgan Rogers.
Having not beaten the Gunners since August 2021 and with the North Londoners going nine league meetings without tasting a defeat since then, there couldn't have been a more perfect start to the game for the visitors.
A fourth goal in the opening 15 minutes of a Premier League match this season is a record no other team can match, and the West Londoners hadn't lost any of their last eight league games when scoring first.
Martinez working overtime
Despite the setback, Arsenal came storming back and fired off three on-target efforts before Chelsea could re-organise themselves into something approaching a cohesive unit.
Before 20 minutes was on the clock, Emi Martinez had already made five saves to keep the hosts at bay, and the Argentine custodian will have been thankful for Wesley Fofana's contribution on the day, as the defender was the only one of Chelsea's back four to win 100 per cent of his tackles.
Two interceptions were as many as any of his Blues colleagues could manage, and 13 one-on-one duels attempted tells its own story. Fofana was everywhere and a major reason why the flow was eventually stemmed - for a short time anyway.
Havertz scores against his old club yet again
An equaliser was always going to arrive, and when it did, who else but ex-Chelsea man Kai Havertz would be the one to ignite the Emirates?
The German has been in fine fettle of late, and his eight touches in the opposition box were the most of any player from either side, whilst his three shots at goal and two on target were only bettered by Bukayo Saka.
A third goal in five appearances against his former side has meant Havertz quickly becoming public enemy No.1 amongst the Stamford Bridge faithful, too.
Pedro Neto's shot against the woodwork in first-half injury time was about all he could muster in what was a disappointing afternoon for the winger.
Though he had the joint-most final third entries (nine), just 22 passes attempted evidenced how well Arsenal diluted the player's influence.
Hato and Acheampong out of their depth
Perhaps far more worryingly for Alonso, both Jorrel Hato and Josh Acheampong hardly covered themselves in glory in central defence.
The two youngsters had just 50 total touches between them, with neither winning a tackle all afternoon or making a single interception.
When Martin Odegaard hammered Arsenal into the lead early in the second-half, it was Acheampong who stood motionless as the Norwegian nipped in to bury his effort beyond Martinez, though it was defensive partner Hato who was hooked along with Romeo Lavia on the hour.
Lavia is getting back to near his best
Lavia's Chelsea career has been plagued by injury concerns, but he can be reasonably happy with his performance in North London.
A pass completion return of 88.9 per cent, along with a 100 per cent record in both aerial and ground one-on-ones, shows that the combative midfielder is beginning to approach somewhere near his best after an awful run of luck.
Unfortunately, neither he nor any of his teammates were accurate enough when it came to chance creation to be able to get Chelsea back into the game.
The nearest the visitors got to an equaliser was when David Raya somehow managed to get a hand to Estevao's brilliant dipping effort in the last-minute, but Alonso will have already understood by then that it was too little, too late from his side.
Though he can be pleased with the collective effort - the Blues made more tackles (12 to 10) and won more (six to five) than the hosts - they weren't quite as sharp in the big moments.
Arsenal can, and have, played better, but Arteta will be well satisfied with all three points after a gruelling encounter.