Tries from Andrew Trimble, Nick Williams and a Penalty Try handed Ulster a 27-19 victory over Leinster at Ravenhill on Friday.
Christmas arrived early for Ulster in this pulsating game at Ravenhill, bringing some much needed festive cheer to a troubled city.
Ulster have firmly established themselves at the pinnacle of the Pro 12 and, in so doing; have exacted timely revenge for last season's Heineken Cup final defeat.
In typical fashion, it was Ulster who made the more productive start, and appeared like a team determined to make amends for last week's disappointing performance.
The home team began by carrying the ball with reckless abandon, and the opening minutes were characterised by terrific continuity and physicality.
This intense pressure from the home team yielded a penalty on four minutes, but fly-half Paddy Jackson was off radar with the kick. His effort was characteristic of a troubled evening with the boot, and the young number ten seemed to be carrying a leg injury.
All things considered, it may have been more prudent to entrust the kicking duties to Pienaar. As it was, it was the European champions who opened the scoring on 11 minutes, when the superb Ian Madigan banged over a penalty following an extremely dubious penalty decision at scrum time.
The away team were playing a higher tempo game, and their preferred mode of attack involved keeping the ball in hand. The men in blue went through phase after phase, looking to exploit holes in Ulster's much vaunted defence.
Their pressure started to pay dividends and Madigan extended the lead with another penalty on 18 minutes. But Ulster refused to panic and they thoughtfully felt their way into the game.
Jackson made up for his earlier miss on 25 minutes, when he slotted a penalty following outstanding work by the Ulster scrum. Indeed the scrum proved a very potent weapon indeed, with Tom Court in particular causing extreme difficulty for his international team-mate Michael Bent.
The scrummaging performance was a much needed boost following their under-par performance against the Saints. Pienaar levelled the scoreline on 29 minutes, having taken over the kicking duties from the unfortunate Jackson.
Ulster's scrum turned the game on its head on 37 minutes, when referee Clancy awarded a Penalty Try following an almighty shove by the Ulster eight.
The second half witnessed better fluidity from the Leinstermen, but the Ulster scrum remained utterly dominant. Rarely has a Leinster pack been humbled in such a manner. Madigan did narrow the gap to 13-12 on 42 minutes, following an appalling Ulster restart.
But the home team responded magnificently, with Nick Williams burrowing over for a try on 42 minutes, helped by the intervention of the TMO. Ulster were now 20-12 to the good. Pienaar fell short with an attempt on 63 minutes, and Madigan likewise misfired shortly after.
The final minutes of the encounter witnessed a massive rearguard effort by the home team. It is fair to say, however, that the sin-binning of Rory Best was something on an injustice. Trimble put the game beyond doubt with a well taken finish, the result of a beautiful cross-field kick by Pienaar.
Ulster's resistance could only last for so long, and McFadden scored a deserved consolation on 77 minutes. But don't let the scoreline fool you. The European kingpins had been decimated in this Christmas cracker at Ravenhill.
Can you hear that sound? It's the balance of power shifting in Irish rugby.
Tries: Penalty, Williams, Trimble
Pens: Jackson, Pienaar
Cons: Pienaar 3
Yellow Card: Best
Pens: Madigan 4
Ulster: 15 Jared Payne, 14 Andrew Trimble, 13 Darren Cave, 12 Luke Marshall, 11 Craig Gilroy, 10 Paddy Jackson, 9 Ruan Pienaar, 8 Nick Williams, 7 Chris Henry (c), 6 Robbie Diack, 5 Neil McComb, 4 Iain Henderson, 3 John Afoa, 2 Rory Best, 1 Tom Court.
Replacements: 16 Rob Herring, 17 Callum Black, 18 Adam Macklin, 19 Alan O'Connor, 20 Roger Wilson, 21 Paul Marshall, 22 Paddy Wallace, 23 Adam D'Arcy.
Leinster: 15 Noel Reid, 14 Andrew Conway, 13 Brendan Macken, 12 Gordon D'Arcy, 11 Fergus McFadden, 10 Ian Madigan, 9 Eoin Reddan, 8 Jamie Heaslip, 7 Sean O'Brien, 6 Kevin McLaughlin, 5 Devin Toner, 4 Leo Cullen (capt), 3 Michael Bent, 2 Sean Cronin, 1 Cian Healy.
Replacements: 16 Aaron Dundon, 17 Heinke van der Merwe, 18 Jamie Hagan, 19 Tom Denton, 20 Rhys Ruddock, 21 Isaac Boss, 22 Andrew Goodman, 23 Adam Byrne.
by Rory McGimpsey