Despite being the side with more changes, Arsenal were quick out of the blocks as usual, and it was Leandro Trossard asking the more serious questions in the early going.
Making his first start for the Gunners since moving from Brighton, the Belgian showed some trickery and earned himself some vital space, allowing him to find Takehiro Tomiyasu on the edge of the area.
Trossard continued to torment City as the first-half minutes ticked by, frequently exploiting the space left by Rico Lewis on the hosts’ right flank.
The winger also had an effort of his own at the midpoint of the half, but Ortega was equal to the task once more.
Creator-in-chief Kevin De Bruyne came closest to finding the net for City, as his curler from the edge of the area drifted narrowly wide of the far post.
A cagey resumption after the interval saw defences on top, with Fabio Vieira’s wayward volley the only effort on goal within the first 15 minutes of the second half.
City substitute Julian Álvarez sparked the contest into life when his long-range effort struck the post, and Arsenal’s failure to clear their lines after this huge let-off cost them the opening goal.