Eric Black's men, who had knocked four past Burnley on Saturday, showed the visitors no mercy as they scored with almost every attack.
It took them just over a minute to rattle in their first and from then on it was almost one-way traffic.
Bjarni Gudjonsson started the onslaught with a stunning goal in the second minute. Gary McSheffrey chested the ball down to the Icelandic international who looked up and then bent a 20-yard effort around Andy Lonergan.
Preston did try to counter their poor start and it took a good save from Scott Shearer to deny Richard Cresswell.
But any hopes the Lancastrians had were extinguished in two minutes as Coventry sliced through their defence.
Their second, in the eighth minute, rounded off a sweeping move which saw McSheffrey and Gudjonsson combining to set up Michael Doyle who scored from a tight angle.
McSheffrey decided to get in on the act in the tenth minute when he rammed home a right-foot shot after Julian Joachim had flicked on a cross from the on-loan Brian Kerr.
Every time Coventry swarmed forward they looked capable of scoring and they added a fourth just short of the half-hour.
This time there was a slightly more direct approach - Scott Shearer kicking long for Joachim who crossed to Gudjonsson who headed home high into the net.
Preston, to their credit, did not deserve to be trailing by such a deficit and were, arguably, the better side on the ball.
Almost inevitably Coventry could not maintain the momentum and Ricardo Fuller pulled a goal back two minutes after the restart after McSheffrey made a hash of a clearance.
There was still more drama to come and with 14 minutes left Cresswell was red carded for a tussle with Calum Davenport inside the penalty area.
Preston boss Craig Brown was also ordered from the touchline after walking 30 yards to register his protest.
Finally, in the final minutes, Lonergan denied Gudjonsson his hat-trick when he saved his spot-kick.