The scoreline flattered fellow promotion contenders Coventry, who were firmly second best and could have conceded half a dozen if not for a handful of stunning saves from Keiren Westwood.
Seyi Olofinjana's cool finish was the only breakthrough of a dominant first half for the Bluebirds, who were well and truly back to their best.
And although Coventry put up a fight after the break, it was the inspirational Craig Bellamy who grabbed a deserved goal courtesy of a deflected effort late on.
The visitors could have no complaints about the result though as Cardiff, watched by a sell-out home crowd, claimed their first Boxing Day victory for 11 years.
Encounters between the two sides have become grudge matches in recent seasons, with the October meeting proving no exception.
Former Sky Blues duo Bellamy and Jay Bothroyd were both handed hot receptions upon their returns to the club before the latter netted a dramatic winner in a 2-1 triumph.
Afterwards, Bothroyd - nursing a foot wound - used his Twitter account to say "I hate playing Coventry. They should put up rugby posts" and "Coventry tried to bully us".
The England international missed the chance to be reminded of those comments having not fully recovered from a hamstring injury, while Cardiff manager Dave Jones handed a debut to centre-back Chris Riggott along with starts for Michael Chopra and Stephen McPhail.
Opposite number Aidy Boothroyd also made three changes from last time out, captain Lee Carsley returning from suspension in the middle of the park along with Jordan Clarke on the right and Lukas Jutkiewicz in attack.
The hosts started brightly and Chopra drilled narrowly wide before Westwood produced a great reflex save to keep out Riggott's left-footed flick from Peter Whittingham's set-piece.
And it came as no real surprise when Olofinjana side-footed home from the penalty spot, meeting Bellamy's low cross after he had latched onto a quick free-kick from Andy Keogh to burst past Richard Keogh down the left.
Westwood was at it again after the opener, twice denying Chopra with superb saves in the space of 10 minutes as Cardiff's free-flowing attacking play continued to cause all sorts of problems.
Coventry emerged with more urgency after the restart but it was not long before Westwood was called upon again to produce a reaction stop from Bellamy.
Boothroyd turned to substitutes Clive Platt and Freddy Eastwood in an attempt to try and inject some attacking impetus and the visitors were certainly making more of a game of things.
Another top-drawer save from Westwood left Chopra wondering what he had to do to beat the Republic of Ireland goalkeeper.
The next goal could have come at either end and Eastwood fired into the side-netting.
But it was left for Bellamy to grab the goal he deserved, via a deflection off James McPake, before being denied a quick second by that man Westwood.