Jonah Lomu got his first Blues try on his league debut as the home side crushed the struggling Dragons in front a record Celtic League crowd.
Blues (26) 41
Tries: N Robinson, C Morgan, R Powell, Lomu, R Thomas, R Williams
Con: N Robinson
Pens: N Robinson (3)
Dragons (11) 23
Tries: Brew, R Thomas, Bryant
Pens: Sweeney (2)
The All Black legend powered through Gareth Chapman's tackle in the 41st minute to delight the fans in Cardiff.
Nicky Robinson, Craig Morgan, Ryan Powell, Rhys Thomas and Rhys Williams also crossed in an Arms Park rout.
Nathan Brew, Rhys Thomas and Jon Bryant got Dragons tries, but the visitors saw Wales back Kevin Morgan badly injured.
The Blues had made a disastrous start as Tristan Davies spilled the kick-off.
Gareth Cooper broke and fed Brew, who coasted over for a try with 18 seconds on the clock.
Blues fly-half Robinson hit back with a superb individual score, chipping over the top of the defence in midfield and beautifully controlling the grubber kick through.
His grounding of the try looked controversial, but referee Phil Fear awarded the score.
An injured Kevin Morgan had made a weak attempt to stop Robinson, and the full-back limped off immediately afterwards with a badly damaged ankle to the concern of watching Wales coach Mike Ruddock.
Craig Quinnell then sent Craig Morgan in at the corner with a suspiciously forward pass, before first Davies and then David Maddocks were sent to the sin bin for offside offences.
With half-time approaching Lomu flattened Dragons wing Chapman, setting the platform for Powell to cross for the third home try.
The fans only had a minute of the second half to wait for the moment they had come to see as the Blues moved the ball smoothly across the three-quarter line.
Prop Martin Jones was on hand to spin a beautifully weighted pass to Lomu, and the All Black legend had the power and pace to drive though Chapman's despairing challenge.
The score gave the home side a bonus point, and as the visitors wilted Wales hooker Rhys Thomas crossed in the corner.
His Dragons namesake - prop Rhys Thomas - got a short-range try for the Gwent side, before a forceful Bryant hand-off on Robinson got the centre a score under the posts.
Thoughts of a comeback were swiftly doused as man-of-the-match Lomu went for the corner before freeing Rhys Williams for a try.
To complete the Dragons' misery, Brew left the field with a broken thumb and Ceri Sweeney was sin-binned for an offside offence with three minutes to go. But the night was all about Lomu.
Blues wing Jonah Lomu:
"All my wishes and dreams are coming true - I didn't know whether to put the ball down for the try!
"There was a lot of pressure on the boys who hadn't played in the win at the Ospreys and we showed our character and strength in depth.
"It's been a hard road for me, but I'm just grateful to my wife, my friends, the Blues and the Welsh crowd.
"Things are coming slowly each week and I'm feeling great - it's only onwards and upwards from here."
Dragons captain Michael Owen:
"We showed more spirit than against the Scarlets and fought back in the second half, but we couldn't see it through.
"Silly mistakes cost us, that's been the story of our season.
"It's all a matter of time, we've got really good players here, the coaches are working hard and we'll get there in the end.
"The injuries are disappointing, but we've just got to get on with it and back the people who are playing."
Cardiff Blues: Rhys Williams (capt); Craig Morgan, Jamie Robinson, Tristan Davies, Jonah Lomu; Nick Robinson, Ryan Powell; Gethin Jenkins, Rhys Thomas, Martin Jones, Craig Quinnell, Robert Sidoli, Andy Powell, Robin Sowden-Taylor, Xavier Rush.
Replacements: Goodfield for R. Thomas (71), M. Williams for A. Powell (68), Phillips for R. Powell (58), Warren for N. Robinson (71). Not Used: B. Evans, D. Jones, Stcherbina.
Newport-Gwent Dragons: Kevin Morgan; Gareth Chapman, Hal Luscombe, Jon Bryant, Nathan Brew; Ceri Sweeney, Gareth Cooper; David Maddocks, Andrew Brown, Gethin Robinson, Luke Charteris, Peter Sidoli, Andrew Hall, Chris Davies, Michael Owen (capt).
Replacements: Black for Maddocks (50), R. Thomas for Robinson (50), Griffiths for Charteris (50), Oakley for Hall (73), Fussell for Brew (39), Warlow for Morgan (22). Not Used: Shelbourne.
Referee: Phil Fear (WRU).