The result strengthens the Bulls' URC playoff hopes as they head into the final round, while Cardiff will be left to reflect on a game that slipped out of their hands in the opening 40 minutes.
It wasn't a perfect evening for Jake White's side, however, as flyhalf Johan Goosen got caught up in a maul and suffered a suspected knee injury, forcing him off the field - though Keagan Johannes looked good after coming on as his replacement as early as the 12th minute.
The hosts blew Cardiff away in a ruthless first half, racing to a 31â-0 lead by the break thanks to tries from Harold Vorster, Wilco Louw, Canan Moodie, and Cameron Hanekom. Goosen converted the first try and added a penalty, before Johannes added three more conversions after replacing him.
Cardiff struggled to match the Bulls' pace and physicality, their defence repeatedly splintered by quick handling and well-timed offloads. The visitors' only first-half highlight was managing to stop further damage despite the Bulls dominating territory and possession.
Winger Sebastian de Klerk continued the Bulls' onslaught early in the second half with two well-worked tries in quick succession, his second coming after a deft offload by Willie le Roux, to extend the lead to 45-0.
To their credit, Cardiff showed resilience in the final quarter, scoring three late tries through Alex Mann, Teddy Williams, and Gabe Hamer-Webb. Ben Thomas converted all three efforts, giving the scoreline a more respectable gloss and offering hope of a potential bonus point that never came.
Despite the late flurry from Cardiff, the Bulls had done more than enough to seal a convincing win. Le Roux was instrumental from fullback, orchestrating attacks and setting up tries with vision and poise, earning him the Man of the Match award. Johannes, stepping in after Goosen's early exit, impressed with his kicking accuracy and game management.