Gunners boss Arsene Wenger had called for a response following last week's shock Capital One Cup penalty shoot-out defeat at Bradford - and got it as the visitors surged into a 3-0 half-time lead following Lukas Podolski's well-taken goal and a brace from Cazorla.
The Spaniard completed his treble on the hour, and although the Royals rallied with goals from substitute Adam Le Fondre and Jimmy Kebe, Arsenal made sure there would be no late drama when Theo Walcott slotted in a fifth with 10 minutes left to close within two points of Tottenham.
In a sign of what was to come, the visitors were quickly on the offensive as midfielder Alex Oxlade-Chamberlain tested Royals keeper Adam Federici with a rasping drive. Walcott then tried his luck with a 25-yard free-kick which bent around the wall, but also wide of the far post.
Royals striker Noel Hunt then headed over from a corner but Arsenal were ahead on 14 minutes. Gibbs pushed forwards down the left channel and clipped the ball through to Podolski, who expertly took the bounce in his stride to leave two defenders trailing in his wake before smashing a left-foot shot past the keeper.
It was 2-0 on 32 minutes as Podolski charged down the left channel before chipping the ball back through the six-yard box where Cazorla arrived to head past Federici. And before the Royals could mount any sort of fightback, Arsenal were 3-0 up.
Walcott's cross from the right was nodded back by Gibbs and Cazorla, with his back to goal, turned to hook the ball into the bottom corner. Walcott split the Reading defence again with his pace at the start of the second half, latching onto an angled ball from Jack Wilshere, before cutting the ball back goalwards, which Adrian Mariappa hacked off the line.
The Royals defence was breached on the hour as Cazorla grabbed his hat-trick, drilling the ball in at the far post after Wilshere had released Podolski down the left. On 66 minutes Le Fondre pulled a goal back by rounding Wojciech Szczesny after he had been played in by Jay Tabb.
Reading closed further with 20 minutes left when Kebe slotted home after beating the offside trap from a pass by Hal Robson-Kanu. But hopes of a remarkable comeback were dashed with 10 minutes left when Walcott was released by Cazorla, and the England midfielder stepped back inside before slotting a curling effort into the far corner.