Arteta fielded Swiss midfielder Granit Xhaka at left-back while he also started without a recognised striker, with Emile Smith Rowe in the most advanced role and Pierre-Emerick Aubameyang coming off the bench.
The Gunners went behind 2-0 after half an hour and were reduced to 10 men after Dani Ceballos' 57th minute sending off.
But Arsenal pulled a goal back from Nicolas Pepe's 73rd minute spotkick after Bukayo Saka was tripped inside the box claiming a precious away goal.
"It's the way we prepared for the game," the Spaniard said at the post-game press conference about his selection decisions.
"It's the decision that I made, thinking that it was the best way to play, but the game was conditioned after four minutes so it was difficult to assess whether it would work or not.