Cardiff Blues stormed to the top of the Magners League on Friday with a crushing 27-11 bonus point win over Leinster.
The win denied Leinster any chance of the Magners League title, but the Blues will have to rely upon the Ospreys losing at Border on Saturday if they are to take the champagne off ice, an unlikely event indeed.
Still, the win guarantees wales a 1-2 finish in the Magners League, a more encouraging sign for the coutntry than their Six Nations campaign was this year.
For Leinster, the defeat was once again an indictment of their lack of big-game temperament, and of an authoritative pack to complement their world-class back-line.
As in Wycombe in the Heineken cup against Wasps, and in Gloucester in the final Heineken Cup pool match, Leinster's forwards failed to provide steady, secure possession and the backs, most of whom were two minutes away from a Grand Slam for Ireland in the Six Nations, were left horribly exposed.
That said, some of the defence in the three-quarters was shocking, and some of the attempted off-the-cuff moves even worse. Never mind his try that nearly gave Leinster fresh hope five minutes later, Shane Horgan's error for Cardiff's killer fourth try was nothing short of amateur.
The Blues would be worthy champions on the back of this performance should the Ospreys somehow throw it away. Their domination of the contact zone, particularly in the first half, was admirable and was spear-headed by skipper Xavier Rush's magnificent charges.
Nick Robinson varied the play superbly from fly-half, and the backs never once let up their concentration, ensuring that even the excellent Gordon d'Arcy did not get the vaguest sniff of the line.
Leinster had the lion's share of possession and territory in the first half without turning it into points and then, as their dream slipped away, their play became ever more ragged.
The Blues, with an unbeaten home record to protect, left no doubt about their intentions, crossing for a superb try after just five minutes.
Following a driving line-out fly-half Nicky Robinson, with a point to prove after being omitted from the Welsh tour party for Australia, knifed between opposite number Felipe Contepomi and flanker Keith Gleeson and sent the supporting Robin Sowden-Taylor over.
Contepomi responded with a penalty but Leinster, desperate for tries, spurned further kicks at goal to go for position with only solid Blues defence - notably one tackle by Jamie Robinson on the burly Shane Horgan - keeping them at bay.
When the Irish province were awarded another penalty after Rob Kearney brilliantly reclaimed his own high kick, Contepomi opted to take the three points.
It was ironic therefore when the Blues, on a rare visit to the Leinster 22, chose to put a kickable penalty into touch and the pack carried hooker Gareth Williams over for a second touchdown.
And the Blues went further ahead early in the second period with an inch-perfect cross kick by Nicky Robinson being caught by Chris Czekaj, who drew the last defender to send fellow wing Rhys Williams in and Ben Blair converted.
A disastrous error by Horgan gifted the Blues a fourth try and a bonus point. The centre tried to chip Marc Stcherbina, but his kick was too low and the Australian centre grabbed it and strolled over for Robinson to add the extras.
Horgan quickly made up for his mistake, hacking the ball downfield for 50 yards and, once Williams had failed to clear, the big centre won the race to touch down.
Contepomi missed the conversion and his evening went from bad to worse when he was dispatched to the sin-bin after taking out Jamie Robinson in mid-air as the Blues man jumped to claim a high kick.
The visitors hurled the ball around in desperation but never looked like reducing the deficit.
For Cardiff Blues:
Tries: Sowden-Taylor, Gareth Williams, Rhys Williams, Stcherbina
Cons: Nick Robinson 2
Pens: Contempomi 2
Yellow card: Contempomi (Leinster, 57, mid-air tackle)
Cardiff Blues: 15 Ben Blair, 14 Rhys Williams, 13 Jamie Robinson, 12 Marc Stcherbina, 11 Chris Czekaj, 10 Nick Robinson, 9 Mike Phillips, 8 Xavier Rush (c), 7 Robin Sowden-Taylor, 6 Mark Lewis, 5 Robert Sidoli, 4 Deiniol Jones, 3 Gary Powell, 2 Gareth Williams, 1 Gethin Jenkins.
Replacements: 16 Scott Roberts, 17 T Rhys Thomas, 18 Scott Morgan, 19 Rhys Shellard, 20 Wayne Evans, 21 Nick Macleod, 22 Tom James.
Leinster: 15 Girvan Dempsey, 14 Rob Kearney, 13 Shane Horgan, 12 Gordon D'Arcy, 11 Denis Hickie, 10 Felipe Contepomi (c), 9 Guy Easterby, 8 Jamie Heaslip, 7 Keith Gleeson, 6 Stephen Keogh, 5 Malcolm O'Kelly, 4 Trevor Hogan, 3 Will Green, 2 Bernard Jackman, 1 Reggie Corrigan.
Replacements: 16 Stan Wright/Cian Healy, 17 Brian Blaney, 18 Owen Finegan, 19 Cameron Jowitt, 20 Chris Whitaker, 21 Christian Warner, 22 Luke Fitzgerald/Kieran Lewis.
Referee: Malcolm Changleng (SRU)
Touch judges: Phil Fear (WRU) Gwyn Morris (WRU)