They also took on a Liverpool team having to make do without goalkeeper Alisson, with free transfer Adrian slotting in between the sticks.
The game started at a frenetic pace, with the hosts setting a high tempo which penned Arsenal back in the final third.
Another encouraging note for Unai Emery's side, meanwhile, was the performance of summer signing Nicolas Pepe.
The worst example was when Dani Cebellos, pinned in near his own corner flag, cleared the ball straight to Sadio Mane 15 yards out only for the Senegal worldwide to shoot straight at Bernd Leno.
Arsenal faced Liverpool on Saturday and everyone was eagerly waiting to see the front three of the gunners for the first time together but Unai Emery chose to use only Aubameyang and Pepe, and benched Lacazette. The two strikers were Aubameyang and Pepe so there wasn't any way that Lacazette would have been put in this position unless Unai Emery chose to play him in instead of Dani Ceballos. The reflex is in one second you turn, you do and you take out.
With Jurgen Klopp's side leading 1-0 at the time, the Brazilian pulled the Egyptian's shirt in the box to allow Salah the chance to hand the Reds a two-goal lead in the late kick-off, an opportunity he duly accepted.
Instead, Liverpool cranked up the pressure before the break and got the breakthrough on 41 minutes when Trent Alexander-Arnold's corner was met powerful by Matip's head.
"I think the second half was much better than the first half".
The Egypt global confidently dispatched the penalty and added a second by brilliantly putting the seal on a three-pass move which eliminated most of the opposition.
Lacazette, scorer of 19 goals last season and one in one match this, was not introduced until the 81st minute - and even then it was Torreira who eventually found the net, drilling home a loose ball 15 yards out.