IF Arsenal were hoping to appoint a lucky general in Mikel Arteta, then the early indications are not good.
The new manager’s maiden home match was threatening to yield a first Premier League victory at the Emirates since October 6, when the Gunners led after 83 minutes.
Mesut Ozil had worked his conkers off, David Luiz was defending in a way so unrecognisable to his old Chelsea team-mates that he might as well have been wearing a Groucho Marx mask and a new-boss bounce was very much evident.
Then a major brain-freeze from keeper Bernd Leno allowed Chelsea to equalise through Jorginho — the sub who clearly should have been shown a second yellow card for a tactical foul just minutes earlier.
If that was unfortunate, what happened next was of greater concern for the Arsenal manager.
As soon as Frank Lampard’s Blues had equalised, belief drained visibly from Arteta’s team and audibly from Arsenal’s ever-pessimistic support.
Three minutes later, Tammy Abraham swivelled in the box and nutmegged Leno for a breakaway winner.
It was Arsenal’s fourth straight defeat here in all competitions — their worst home run in 60 years.
For Lampard, this was a second away win at a major London rival in successive Sundays — which was just as well, given Chelsea’s home form.
Lampard and Arteta were midfield rivals during the glory days of Wenger-Mourinho grudge matches.
Both sides have slipped out of title contention, though Arsenal tumbled further and surely face another season out of the Champions League after falling 11 points adrift of the top four.
Much more of this and we’ll soon be asking whether Arsenal are too good to go down. They are, of course, but it would be a weird one to even have to ponder. It was Lampard, not Arteta, who showed sufficient wit to reshape his team mid-match and change the tide of the contest.
Chelsea triumphed at Tottenham with a back three, yet they were over-run by Arsenal when employing the same system.
Lampard sent on Jorginho after just 34 minutes, switched to a back four — and saw the Blues dominate the remainder of the match.
The Chelsea boss claimed it had more to do with increased desire than tactical tweaking, either way the change was dramatic.
Arsenal started with a workrate and tempo rarely seen under Unai Emery and Luiz was wide with a scissors kick before Pierre-Emerick Aubameyang nodded the opener.
Ozil’s corner was nodded on by Calum Chambers and Aubameyang leant backwards to head home.
Alex Lacazette ought to have made it 2-0 but pondered and squandered his chance after a swift break from Reiss Nelson and Aubameyang.
Ozil was joining the high press like never before and, more characteristically, produced a gorgeous chested knock-down — suggesting the man has ribs made of velvet.
On came Jorginho for left-back Emerson, with Fikayo Tomori to right-back, soon to be replaced by another Blues kid, 19-year-old Tariq Lamptey, who made an impressive debut.
And from there, Chelsea were tented up in the Arsenal half for most of the match, without creating much.
Lamptey’s angled pass for Abraham was their most incisive moment — but the young England striker was denied by an excellent Luiz block.
After Ozil — actually sweating — was replaced by Joe Willock on 75 minutes, Arsenal began to sit back.
Then came the moment referee Craig Pawson will not look back upon with any great pride.
Jorginho, already booked, made a clear-and-obvious tactical foul to halt an Arsenal break with a tug on Matteo Guendouzi. Pawson was either unsighted or he bottled it — and Arsenal paid a severe price.
When Mason Mount swung over a free-kick from the left, Leno decided to come off his line with a confidence which was extraordinarily misplaced.
The German barely reached the same postcode as the ball and a grateful Jorginho stabbed home after a tangle with Lucas Torreira, which left the Arsenal man floored and the goalscorer unmarked.
The winner came courtesy of a sharp break from Willian and Abraham, who exchanged passes twice before the Englishman turned and snaffled his 12th league goal of the season to tighten Chelsea’s grip on a Champions League place.
Arteta, a veteran of some of Arsene Wenger’s darker days, will have recognised days like these all too well.
When defeat is seized from the jaws of victory, when low farce reigns in the Arsenal box — and when the moaning from Arsenal’s Eeyore tendency batters your eardrums in great waves.
To turn around this crisis, Arteta will require greater fortune than he received yesterday.
But he’s going to need an awful lot more than just luck as well.