Kitson took his tally for the season to 12 goals, clinically punishing Brighton after they had been reduced to ten men by the dismissal of teenage debutant defender Gary Elphick.
Brighton had initially made life difficult for the leaders, setting up with five at the back and trying to frustrate the high-flying home side.
But Reading made the breakthrough on 28 minutes, taking the lead without having had a shot on target courtesy of Charlie Oatway's own goal.
Glen Little was the architect, skipping past Alex Frutos and hitting a firm low cross against the legs of the Brighton skipper, who could only watch as the ball bobbled past stranded keeper Alan Blayney.
And if that was the goal that wounded Brighton, Kitson was the man to rub in the salt.
Three minutes later, Guy Butters' intervention prevented Reading doubling their lead, the central defender just getting ahead of Kitson to cut out Bobby Convey's dangerous cross.
But the game was as good as over within five minutes of the restart. Eighteen-year-old Elphick's first start for Brighton was ruined when he picked up a second booking for blocking Kitson as the striker looked to run clear.
Two minutes later, Kitson tumbled again under a Gary Hart challenge and despatched the resulting penalty himself to double Reading's advantage.
The big striker was on target again 19 minutes from time, reacting quickest to nod past keeper Blayney after Nicky Shorey's shot had deflected skywards.
Steven Hunt added a fourth on 76 minutes, heading home Shorey's cross at the far post for his first goal for the club.
Brighton substitute Colin Kazim-Richards pulled one back with the best goal of the game, driving home from 30 yards after intercepting Steve Sidwell's crossfield pass, but that was scant consolation for Mark McGhee's side.
Sidwell made amends in stoppage time, rounding keeper Blayney and crossing for Kitson to head home for his hat-trick, his effort crossing the line before Hunt made sure.
Reading's seventh straight win keeps Coppell's side four points clear of second-placed Sheffield United, but more importantly stretched the gap between first and third places to a massive 17 points.