It was Swansea that raced into an early lead thanks to the boot of Aled Lewis but Cardiff's monster pack proved the difference as Nicholas Huntley, Arthur Ellis and Jake Woolley Cooper thundered over.
Cameron Pimlow pulled the strings from fly-half and kept the scoreboard ticking over before Jackson Szabo hit-back for Swansea.
But Cardiff finished with a flourish with man-of-the-match Craig Lodge crashing over and live-wire wing Rhys Howells scampering over in the corner.
The victory caps an impressive season for Cardiff, who returned to the premier division of university rugby and have now completed a hat-trick of victories over their big-rivals in 2011-2012.
Swansea had the first opportunity to put points on the board after Huntley was penalised at the breakdown and Lewis slotted the penalty to hand the reigning champions the early advantage.
Cardiff responded with sustained period of pressure but were unable to break Swansea's steadfast defence and Lewis stretched his side's lead further following a strong break from Lewis Chance.
Pimlow squandered the chance to hit back for Cardiff on 17 minutes but they were soon on the scoreboard with thanks to Huntley.
Will Jones made the initial inroads and combined with Rhys Howells before the second-row powered over.
Pimlow was narrowly off target with the touchline conversion but the try brought the capital city outfit within a point of Swansea.
And Cardiff surged into the lead on the half-hour mark after their formidable pack flexed its muscle again.
Captain Cooper Woolley almost bulldozed through from a slick lineout move but Ellis was on hand to crash over.
Pimlow added the extras and landed a drop-goal on 33 minutes to extend Cardiff's lead.
Swansea were dealt a further blow on the stroke of half-time as their Cardiff RFC scrum-half Tom Rowlands was sin-binned for a professional foul.
Pimlow failed to punish Rowland's indiscretion from the kicking-tee and the score remained 15-6 at the interval. But the environmental engineering student got the scoreboard ticking again with a neat drop-goal on 44 minutes.
Martin Fowler's men then took a major step towards victory as Cooper Woolley crashed over from an identical lineout move to the one that led to Ellis' score.
Swansea continued to battle to keep the clash alive but despite dominant periods of territory and possession they failed to cross the whitewash.
Cardiff's Ellis was sent to the sin-bin on 59 minutes as the penalty count began to rack up.
Szabo powered through the Cardiff defence to score in the corner and Lewis landed the conversion to hand Swansea a glimmer of hope.
But Cardiff finished in style with late tries from Lodge and Howells to seal a convincing 33-13 win.
Swansea: E Jones; J Szabo, L Chance, M Jones, T Bonnell; A Lewis, T Rowlands; C Francis, R Clancy, I Williams, R Smart, J Barley, J Vaughan, R Tucker, S Lewis
Replacements: G George, S Jones, K O'Sullivan, M Thomas, I Griffiths, H Jafari, J Hammett, L Dickerson
Try - J Szabo. Con - A Lewis. Pens - A Lewis (2)
Cardiff: C Simpson; W Jones, E Jones, R Wardle, R Howells; C Pimlow, J Macdonald; B Thayer, R Grimstone, J Cooper Woolley, N Huntley, C Lodge, J Wood, J Thomas, A Ellis.
Replacements: G Lewin, J Pincott, L Jones, L Bray, R Luckwell, A Devereux, M Purcell, M Woodward, S Morgan, J Casella
Tries - N Huntley, A Ellis, J Cooper Woolley, C Lodge, R Howells. Con - C Pimlow. Pen - C Pimlow. Drop Goal - C Pimlow.
