Aaron Ramsey returned to haunt old club Cardiff by netting twice in a 3-0 win that sees the league leaders move seven points clear at the top.
The Wales midfielder continued his blistering run of form when he was alert to guide Mesut Ozil's cross over home goalkeeper David Marshall with a looping header on 29 minutes.
Substitute Mathieu Flamini put a gloss on the scoreline when he bounded onto another Ozil pass to thump the ball beyond Marshall on 86 minutes from 14 yards.
Ramsey contributed his second goal of the day two minutes into injury time and his 13th goal in all competitions this season when he walloped into the net from substitute Theo Walcott pass with Cardiff caught on the break.
Ozil has now unearthed more assists than any other Premier League player this season since his £42 million summer move from Real Madrid.
The winning margin was little more than Arsenal deserved for a largely dominant performance that should have earned them more goals, especially in the first half when Cardiff could hardly gain any meaningful period of pressuire.
The home side's best attempt of the match came in the 52nd minutes when Wojciech Szczesny was forced to claw out Fraizer Campbell's header, but Arsenal were a class apart in the key areas against a collection of honest triers.