The Bluebirds were in devastating form at Ninian Park and they put bottom club Huddersfield to the sword with Jason Bowen and Robert Earnshaw bagging a brace apiece.
Bowen fired the hosts ahead on 19 minutes from a Fan Zhiyi pass and just before half-time Earnshaw doubled the tally after latching onto goalkeeper Neil Alexander's clearance.
The Terriers' Danny Schofield was then sent off before the break for a second bookable offence and Bowen bagged his second on 64 minutes.
Earnshaw completed the scoring on 73 minutes and it is a win which puts Cardiff level on points with Bristol City while the defeat will raise further question marks over Mick Wadsworth's future as Huddersfield boss.
Oldham maintained their unbeaten away record and ended Crewe's run of ten games without defeat, with a 2-1 success at Gresty Road.
Carlo Corazzin converted John Eyre's corner on 26 minutes but Rob Hulse levelled the scores on 56 minutes when he headed home Kenny Lunt's free-kick.
The decisive moment came just after the hour mark after Steve Foster fouled Wayne Andrews in the penalty area and David Eyres tucked home the spot kick.
Foster was booked in that incident and seven minutes later received his second yellow card for another foul on Andrews.
Click below for an individual match summary:
Cardiff City 4-0 Huddersfield Town
Crewe 1-2 Oldham
