Ulster took a suffocating grip upon the Pro12 League with this critical win over arch-rivals Leinster at Ravenhill.
The scars from last weekend's European loss remain, but like true warriors they took all that hurt, all that disappointment and poured it into this performance. That it was Leinster in town helped to focus the minds also.
As a spectacle, it was an awful game. In truth, chances were scarce and open play in short supply. But it didn't matter to the essential appeal of the contest. This was a front-up, head-on battle.
Leinster tried valiantly to stand up to the Ulstermen. But they lacked the weaponry to deal with the continuous bombardment of their defences. Ulster were in no mood to be subtle on the night and attacked the Leinster set-piece relentlessly.
In fact, Ulster's pack dictated the terms. Leinster simply could not contain them and the home side turned more and more to their forwards to swing the issue in their favour.
Penalties for Ulster became almost predictable from the scrums and it was significant that all 13 first-half points came through this medium.
Before they gained the upper hand though, they had to suffer through an error-strewn opening quarter as Leinster absorbed the pressure and repelled the repeated attacks. And when Paddy Jackson shanked his first two penalties, Leinster took advantage with Ian Madigan kicking them into a 6-0 lead by the end of the first quarter.
As it stood at the time it was a truly astonishing scoreline. Ulster had all the possession, had been the side running clever angles and were absolutely dominating the physical exchanges – yet they were in arrears.
Jackson eventually found the target at the third attempt but the early momentum had been lost. It was no surprise when Ruan Pienaar took over the kicking duties from the tee.
But even though the scoreline was in Leinster's favour, they were second best in the open exchanges with Ulster's Nick Williams in particularly belligerent mood.
Williams' work rate has been questioned in the past, but last night he was the perfect battering ram.
Indeed, when he dismissively handed off no less a competitor than Leo Cullen in the first half, it was an indication of his menace, strength and, in terms of the collective, Ulster's greater firepower.
The ferocity of the Ulster attacks and forward play was stunning. They were routinely committing acts of aggression at scrum time and it was entirely predictable that the only try of the opening half would come through their powerful pack.
That it came by way of a penalty try was absolutely in keeping with their superiority, as twice the Leinster front-row buckled under the greater pressure being brought to bear by the home side.
Eventually George Clancy was left with no option other than to run under the posts and signal the score that gave Ulster the lead they so clearly deserved.
Pienaar added the extras and the home side turned over four points (13-9) to the good – the tallies added to by Pienaar and Madigan penalties.
Leinster opened the second half looking like they meant business. They immediately charged deep into the Ulster half and corralled the home side into their own '22'.
Their surge was ultimately parried but before they were forced to retreat they bagged three points through Madigan's boot to make it 13-12.
Leinster were clearly buoyed by their early haul and sought to press home their advantage.
But the multitude of handling errors that frustrated them last weekend came back to scupper their resurgence.
After working the ball systematically into the danger zone they lost momentum where it mattered most – inside the Ulster '22.'
Credit must be given to the home defence and when Williams plucked possession and drove powerfully forward to relieve the pressure there was a real sense of accomplishment about what had just been achieved.
Just minutes later Ulster relentlessly strode into the Leinster '22' and when the play eventually broke up it was absolutely fitting Williams was under a pile of bodies claiming a try.
A quick check upstairs and referee Clancy agreed with the former Aironi player and Ulster were in dreamland.
The home side were in absolute control at this juncture but could not shake loose a dogged Leinster who were resolutely clinging on.
Finally Ulster shook them loose with a classic try.
Pienaar made it possible with a superb cross-field kick that was fielded impeccably by Andrew Trimble and he raced over unopposed.
When Pienaar added the conversion the gap was widened to 27-12 and Leinster's effort looked to have been rendered fruitless.
They rallied, though, and when Fergus McFadden raced over for the final try of the evening they had a sniff of a losing bonus point.
It was not to be, however, as Ulster professionally ran out the clock to extend their Celtic League winning streak to 11 matches.
ULSTER – J Payne; A Trimble, D Cave (A D'Arcy 64), L Marshall, C Gilroy; P Jackson (P Marshall 71), R Pienaar; T Court (C Black 78), R Best, J Afoa, I Henderson (A O'Connor 77), N McComb; R Diack (R Herring 78), C Henry (capt) N Williams (R Wilson (74).
LEINSTER – N Reid (A Goodman 57); A Conway, B Macken, G D'Arcy, F McFadden; I Madigan, E Reddan (I Boss 62); C Healy (H van der Merwe 57), S Cronin, M Bent (J Hagan 62); L Cullen (T Denton 57), D Toner; K McLaughlin (R Ruddock h-t), S O'Brien, J Heaslip.
Ref – G Clancy (Ireland).