Despite fielding a much-changed side ahead of this weekend’s crunch clash with Napoli, Inter were the width of the crossbar away from scoring the opener inside just two minutes, as Denzel Dumfries’ outside-the-boot effort came back off the woodwork.
Hakan Çalhanoğlu then struck just wide from distance moments later, as Arsenal were immediately on the back foot.
However, the Gunners grew into the first half as Bukayo Saka’s shot was gathered by Yann Sommer, but just as they looked as if they had reached the interval unscathed, the visitors conceded a penalty.
Mikel Merino was penalised for handball, allowing Çalhanoğlu to score his 19th successive spot-kick by striking down the middle, giving the hosts a half-time lead.
Arsenal pushed for the equaliser early in the second half, as Gabriel Martinelli’s left-footed shot struck the side-netting before Dumfries cleared off the line from Saka’s corner.
Kai Havertz then unleashed a curler that was destined for the top corner before Sommer tipped it over, before Inter brought the cavalry on just after the hour-mark, introducing the likes of Marcus Thuram and Nicolò Barella.
The Gunners continued to dominate in spite of that, as Havertz’s goal-bound strike was brilliantly blocked by Yann Bisseck.
That said, the visitors failed to create many clear-cut chances, as Inter held on for a fourth consecutive UCL clean sheet to maintain their impressive unbeaten start to the league phase (W3, D1).
In turn, Arsenal lost their unbeaten start after conceding their first goal in the competition, and have now failed to score in their last five UCL outings in Italy.