Connacht produced their best performance of the season to get their Champions Cup qualification hopes and their PRO14 knockout ambitions back on track.
In the process they brought a five-match losing run in the league and Europe to an end in impressive fashion as they held a team scoreless in the competition for only the second time ever.
Cardiff may have been without half a dozen Welsh internationals, with Connacht only missing Bundee Aki to Six Nations duty, but they were outplayed from start to finish.
They only managed to get inside the Connacht 22 for the first time after 57 minutes but then turned over the ball with Peter Robb putting Kyle Godwin away for an 80-metre dash to secure the bonus point.
"I was pleased with the pressure we placed upon them when we didn't have the football," said Connacht coach Andy Friend after the Blues lineout lost 11 of their own throws.
"I haven't looked at the stats yet but I can think of two or three tries that came off their turnovers. It was our pressure that got us the football and we were able to react to that."
Hooker Dave Heffernan produced a superb display after being released from Irish camp to play while Jack Carty was back to his best, dictating the flow of the game from out-half.
They led 15-0 at the break after Heffernan pounced on another lineout giveaway from the Blues to race in from 22 metres after 27 minutes and then seven minutes later Robb collected a neat left-foot grubber from Carty to score in the right corner.
Then replacement prop Denis Buckley showed impressive pace to set up John Porch for his fifth try of the season before Godwin sealed their fifth try bonus of the campaign.
"To not give Cardiff a point, and for us to get the bonus point, that will have an impact at the end of the season," added Friend. "We play Edinburgh twice over the next few months. They are ahead of us. Scarlets are ahead of us, we play them once. And Munster we have got to play them again. It is all in our control but we have got to make sure we keep delivering performances like that, if not better."
CONNACHT - T O'Halloran; J Porch, K Godwin, P Robb (T Daly 59), M Healy; J Carty (C Fitzgerald 65), K Marmion (C Blade 57); P McAllister (D Buckley 49), D Heffernan (S Delahunt 62), F Bealham (D Robertson-McCoy 57); U Dillane, G Thornbury (J Maksymiw 35); P Boyle (E McKeon 65), C Fainga'a, J Butler (McAllister 68-76).
CARDIFF BLUES - D Fish (R Edwards 60); J Harries, R Lee-Lo (B Thomas 31-40 HIA), G Smith (Thomas 65), H Amos; J Tovey, L Williams (L Jones 60); R Gill (C Domachowski 50), L Belcher (K Dacey 48), D Arhip (S Andrews 40); F Paulo (S Davies 40), J Ratti; J Turnbull, O Robinson (Boyde 49 HIA), W Boyde (N Williams 48).
REF - S Berry (South Africa)