Well, that escalated quickly. On a wild, ultimately triumphant night at the Emirates Alexandre Lacazette’s first three touches in the Premier League went as follows: kick-off, goal, kick-off. At the end of which Arsène Wenger’s latest club record signing had been treated to an uncut hit of pure, unfiltered Arsenal-dom, the very essence of late Wengerism crushed into the space of 270 giddy seconds.

By the end a match that might have finished nine-three or 12-all and which contained every Arsenal emotion from giddy, brittle hope, to giddy, brittle collapse had ended in a rollicking 4-3 home victory marked out by a carefree disdain for the prosaic disciplines of defending. And all of this on a deep blue north London evening before the season has even started for 90% of the Premier League. Hello Arsenal my old friend. I’ve come to talk with you again.

Olivier Giroud saves Arsenal from homemade chaos in Leicester thriller Read more

Take a long look, Alex. There is more of this, much more. Stage one: the hope. There are dream centre-forward debuts. And then there is scoring with your first touch in open play as Lacazette did after 90 seconds here.

All it took was a smart little shimmy away from Wes Morgan and Harry Maguire and the coolness to stop and wait in his own small square of Emirates green as Mohamed Elneny curled a cross in from the right.

Lacazette flexed his neck and flicked a poacher’s header into the corner past Kasper Schmeichel’s flailing hand. The home crowd erupted, luxuriating in a deep gurgling bath of welcoming applause as the new man – who cost £52m from Lyon, £10m more than Mesut Özil – emerged from beneath his team-mates’ embrace.

After the hope: the deflation. If Lacazette’s start felt perfectly scripted, then the best scripts also tend to contain a dollop of uncomfortable truth. Within 90 seconds Leicester had equalised. Everyone in an Arsenal shirt ignored Maguire, the most unignorable object inside the Emirates not wearing a green dinosaur costume. His header back found Shinji Okazaki and the ball flashed past Petr Cech on his line.

Next up stage three: the crumple. No doubt Lacazette will have studied his new team even before he joined.

But in practice there is nothing quite like the real thing and here Lacazette got the full nose-frazzling dose of Arsenal snuff as the sense of new eras dawning was shredded by an opponent scenting weakness and gouging it open with a beautifully pure sense of purpose. Granit Xhaka gave the ball away. Marc Albrighton crossed instantly. Jamie Vardy smashed it home from six yards out.

As Leicester’s support erupted, the home crowd turned a little green and seasick. “You’re just a ground full of tourists,” the Leicester fans sang as the game became scrappy, Arsenal’s attacks foundering a little too often on glitches in Mesut Ozil’s passing mechanics. But they are not really. They have just seen quite a lot of this around here, a crowd caught in a constant state of angsty conflict with itself.

And of course, after the downs comes the gloss of hope. With seconds left in the first half and most of those present steeling themselves for the traditional half-time boo, Danny Welbeck equalised, strolling through to tuck the ball past Schmeichel. Both new signings, Lacazette and Sead Kolasinac, were involved in the goal.

And Lacazette did look sharp and ferrety even in that chaotic first half, sniping in to steal the ball high up the field and lurking on the last defender with some purpose.

He also spent quite a lot of time being bumped and jostled by Maguire and Morgan, whose steady metamorphosis into a large piece of handsomely upholstered industrial furniture supported by a dinky pair of legs continues apace. This is to be expected.

Play Video 1:21 Arsène Wenger happy following Arsenal's win over Leicester – video

Lacazette will take a while to adjust. A goal and a win will give him breathing space. Beyond this, what to make of a victory that was spirited and full of attacking vim but which also framed the fault lines that will surely be exposed again under the weight of the Premier League slog?

The final twitches of this game, after Vardy had made it 3-2, saw a genuinely strange (and of course depleted) Arsenal defence, with two left-backs in the centre, a right-back at left-back and a midfielder at right-back. Meanwhile up front the combined craft of Lacazette, Olivier Giroud, Özil, Aaron Ramsey and Theo Walcott kept on suggesting something else, a team half-glimpsed, flickering just behind the fuzziness of late-Wenger Arsenal.

Their slickness and drive was rewarded with, first, an equaliser from Ramsey and then a wonderful headed winner from Giroud to wrench the night back Arsenal’s way and send the home fans into a state of transport at a wonderfully entertaining Premier League frolic.

Welcome Alex. Strap yourself in. Coming up next: more, much more, of various shades of the same.