© Anthony Devlin / PA Photos
© PA Photos
Giroud missed a succession of first-half chances, the first of which was a near-post header from Bacary Sagna's cross that flicked the crossbar.
The two Frenchman combined again soon after as Giroud guided a drilled cross towards the bottom corner, only for Mark Bunn to save well low to his right.
Norwich failed to create anything of note in the first period, but took a surprise lead after the break as Turner climbed unmarked to nod in an inviting Snodgrass delivery.
Arsenal pinned the Canaries back as they went in search of an equaliser and minutes after Theo Walcott had a penalty appeal turned down, the hosts were given an 85th-minute spot kick.
While Kei Kamara's tug on Giroud inside the box was blatant, the incident occurred from an Arsenal corner that should have been given as a Norwich goal kick.
Arteta struck fiercely from 12 yards past Bunn, who was beaten again three minutes later when Giroud poked the ball into the net following good work from Alex Oxlade-Chamberlain.
© PA Photos
Fabianski ensured Arsenal maintained their newly-established advantage with a smart stop from Jonny Howson, and then again by superbly tipping a Snodgrass header over the crossbar.
A counter-attack goal from Podolski, who shot low across Bunn into the far corner, confirmed the result, which sees the Gunners climb above London rivals Chelsea and Spurs in the table.