The Gunners picked up their second win from as many Premier League games at Selhurst Park, following up last weekend's slender win over Nottingham Forest thanks to a second-half Martin Odegaard penalty.
However, Arteta's men had to see out most of the second half with 10 men, as Tomiyasu was controversially given his marching orders for two bookable offences within the space of seven minutes.
The Japanese defender was firstly cautioned on the hour mark for taking too long over a throw-in, before being sent for an early bath for an apparent tug on Jordan Ayew as Palace attempted to counter.
The decision to send Tomiyasu off was widely criticised, as replays showed that there was little contact between the Arsenal man and Ayew, but VAR officials cannot intervene to overturn a second yellow card.
When asked about the incident in his post-game press conference, Arteta claimed that the call was «so obvious», but the Arsenal boss was overjoyed at the resilience his side showed after going down to 10 men.
«I prefer not to make comments because for me it's so obvious,» arsenal.com quotes Arteta as saying. «The decision is made, we are not going to change it now.
»We adapted to it, unfortunately it made the game obviously much tougher and normally you drop points when you have to play in this league for 30 minutes away from home. To survive the way we did is not something that usually happens, but we are so happy that we overcame that big hurdle."
Elaborating on the new rules regarding time-wasting, Arteta stressed the need
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