The Blues threw down the gauntlet to the Ospreys with an eight-try destruction of Edinburgh on Thursday.
Blues (26) 55:
Tries: R Thomas, J Robinson 2, D Baugh, R Williams 2, A Lewis, P Muller.
Cons: I Harris 4, N Robinson 2.
Pen: I Harris.
Edinburgh (22) 22:
Tries: M Blair, A Warnock, C Sharman.
Cons: A Warnock 2.
Pens: A Warnock.
The bonus-point win moves the Blues a point above the Ospreys, who play Glasgow on Friday night, in the race for the last Welsh Heineken Cup spot.
Hooker Rhys Thomas got the first Blues try within two minutes, but also got himself sent-off in the second half.
Edinburgh failed to take advantage, although scrum-half Mike Blair had a fine solo score as a consolation.
The Blues started with keen intent and had their first try on the board within two minutes.
A flowing backs move carved Edinburgh apart down their left flank, before the ball was recycled inside for hooker Thomas to charge over under the posts.
Iestyn Harris, who will now put his feet up for eight weeks to rest a knee injury, popped over the easy conversion and the Blues were up and running.
Blair had not read the script, however, and four minutes later the Scotland scrum-half took a quick tap in his own 22 and raced the length of the field to score, Alistair Warnock missing the conversion to leave the score at 7-5.
The Blues hit back with two more tries before the clock had reached the 15 minute mark, first Harris handing off Warnock to send Jamie Robinson over.
Then Dan Baugh also shoved aside an Edinburgh player - this time Simon Webster - to score in the left corner, with Harris converting both.
Warnock pulled back a try, adding the conversion himself, for the visitors before the Blues reached their first target of four tries for a bonus point.
Wales full-back Rhys Williams found himself one-on-one with opposite number Hugo Southwell and turned on the after-burners to round his man for the fastest bonus point in the Celtic League this season.
At 24 minutes it beat the previous record by a full 120 seconds set, ironically, by the Ospreys against Borders.
Yet Edinburgh came back again, Webster making the extra man on the left to send fellow wing Conan Sharman over behind the posts, Warnock converting and adding a penalty to make it 26-22 at the break.
Although a man short after having scrum-half Andy Moore sin-binned for killing the ball just before half-time, the Blues wasted no time in adding another try.
Craig Morgan came back on the angle to cut the line and Jamie Robinson went over for his second try, again converted by Harris.
It was looking all rosy for the men form Cardiff until the 49th minute when hooker Thomas got himself sent-off for aiming a head-butt at a Scottish opponent.
Coach Dai Young, the former Wales and Lions prop, will be delighted at the way his forwards responded though.
There seemed little evidence the Blues were actually a man light, as the Edinburgh set-piece actually got shunted backwards at the next scrum.
With the bit between their teeth, the Blues worked space for Rhys Williams to again show his pace to the line, Harris missing the afters but adding the Blues' first penalty kick to give the home side a 41-22 lead.
There was just time for Edinburgh to lose Craig Smith to the sin-bin and ship two more tries, replacement Blues hooker Andrew Lewis and centre Pieter Muller going over with Nick Robinson converting both.
Now there comes 24 hours of nail-biting for the Blues and their fans, as they wait to see if all the effort was in vain or if Glasgow will do them a huge favour against the Ospreys at Hughenden.
Blues: R Williams, D Dewdney, J Robinson, I Harris, C Morgan, N Robinson, A Moore, J Yapp, R Thomas, D Crompton, H Senekal, J Brownrigg, D Baugh, M Williams (capt), N Thomas.
Replacements: M Allen, N MacLeod, P Muller, K Fourie, A Lewis, C Quinnell, R Sowden-Taylor.
Edinburgh: H Southwell, C Sharman, T Philip, A Dickson, S Webster, A Warnock, M Blair (capt), A Jacobsen, C di Ciacca, C Smith, G Perrett, A Kellock, A Strokosch, A Hogg, A Dall.
Replacements: A Kelly, J Brannigan, R Mathieson, N Pike, T Blackadder, R Lawson, G Burns.
Referee: Alistair McKay (Ireland).