The Stormers ran in six tries to deal Cardiff's hopes of reaching the United Rugby Championship play-offs a heavy blow with a 40-3 win in Cape Town.
The South African side were ruthless on the counter-attack and took a firm grip with three slick tries in the first half.
Ruhan Nel, Leolin Zas and Manie Libbok all crossed as the hosts opened up a 19-3 half-time lead before Junior Pokomela, Evan Roos, and Rikus Pretorius went over in the second period. Libbok converted four for a 13-point individual haul while Tim Swiel added another.
Cardiff were ragged by the end as Stormers repeatedly cut loose, but it was the Welsh side who started the better. The visitors applied considerable pressure in the opening 15 minutes but an early Jarrod Evans penalty was all they had to show for it.
The opening try came against the run of play as Stormers seized a chance after Cardiff conceded a penalty.
The ball was spread right by a few long passes from Libbok and Warrick Gelant before wing Zas kicked forward and gathered himself to put Nel over on the inside.
Another Stormers try followed after Evans knocked on under a high ball. Zas again showed great improvisation to hack on, and he was presented with a simple scoring opportunity after Seabelo Senatla cleverly palmed the ball back into his possession.
The hosts then took complete control with another superb counter-attacking try. Gelant’s kick was claimed by Libbok, who then charged forward and exchanged passes with Herschel Jantjies to wrongfoot the defence and touch down.
The early part of the second half was a stop-start affair, but Stormers regained their stride around the hour-mark and ran away with the match with three tries in quick succession.
They secured a bonus point after Cardiff lost possession in front of their own posts, and Roos quickly put them on the attack.
Damian Willemse carried the ball close to the line and offloaded for Pokomela to cross.
Roos then got in on the act himself soon after by breaking a tackle and racing clear.
Pretorius then capped a fine afternoon for the Stormers with a long-range score after Cardiff turned over the ball inside their half.
Stormers 40 (19)
Tries: Ruhan Nel, Leolin Zas, Manie Libbok, Junior Pokomela, Evan Roos, Rikus Pretorius
Conversions: Libbok (4), Tim Swiel
Cardiff 3 (3)
Penalty: Jarrod Evans