The Gunners bounced back from their League Cup disappointment at Bradford in emphatic style with a convincing win at the Madejski Stadium.
Arsenal went ahead early on as Lukas Podolski lashed the ball home past Adam Federici after just 14 minutes.
Spanish star Cazorla then took control as he scored two goals in two-minutes just before half-time. The former Malaga man then cemented his claim for the match-ball with his third on the hour mark.
Reading then showed some real spirit as they battled back with two goals of their own with Adam Le Fondre and Jimmy Kebe both slotting home.
But the fairytale comeback never materialised as Theo Walcott - who started the game as a central striker - fired home Arsenal's fifth.
The result moves Arsenal up to fifth in the Premier League table while Reading remain rooted to the bottom and in danger of being cut adrift in the fight to avoid relegation.
The tone was set early as Alex Oxlade-Chamberlain tested Reading goalkeeper Federici early on before Jobi McAnuff squandered a good chance for the Royals at the other end.
Arsenal were ahead on 14 minutes as Podolski was afforded far too much room in the box, before Cazorla scored twice in three minutes as he capitalised on some static defending from the hosts.
Federici did well to keep out Oxlade-Chamberlain again and send the hosts in only three down, but the Australian could do nothing to prevent Cazorla completing his hat-trick by rounding off a brilliant move after the break.
Reading threatened the unlikeliest of comebacks when Le Fondre and Kebe both converted one-on-ones within the space of five minutes, but Arsenal managed to slow things down and calm the nerves.
And the rout was completed when Cazorla turned provider for Walcott, who showed a striker's composure to slot home left-footed into the bottom corner.