The opening goal came inside 15 minutes when left-back Kieran Gibbs, who received a release pass from Cazorla, played an aerial ball into the path of Lukas Podolski from the left with the German producing a brilliant first touch with his right foot before volleying home past Royals keeper Adam Federici with his trusty left boot.
The lead was doubled just after the half-hour mark when Podolski turned provider with a chipped pass into the area which allowed Cazorla to meet the ball with an unmarked diving header from the edge of the six-yard box.
The Spaniard added his second in the 35th minute when he controlled Gibbs' back post header with his back to goal then swiveled and hit a bouncing ball past a despairing Federici.
15 minutes into the second half, Cazorla completed his hat-trick when he simply side-footed Podolski's low ball across the six-yard box to make it 4-0.
Le Fondre got one back for the Royals in the 66th minute when he received a through ball from Jay Tabb after he evaded Jack Wilshere, who had slipped, and then rounded Wojciech Szczesny before Jimmy Kebe grabbed a second five minutes later after good work from second-half inclusion Robson-Kanu.
However, Theo Walcott eased the fears of the Gunners bench by slotting home a clever fifth goal with his left foot after being found by Cazorla in the 80th minute.
The victory was the confidence-booster Arsenal needed ahead of the weekend's trip to Wigan Athletic whilst Reading remain rooted to the bottom of the table as they prepare for the daunting task of taking on Manchester City at the Etihad stadium.
Madejski Stadium, Reading - 24,125