With the title needing to be decided on points difference with Wales, Ireland and the English all in the hunt for the championship, it was the Welsh who kicked off the tournament's Super Saturday with a 61-20 thumping of Italy in Rome.
That sent them temporarily to the top of the table and left Ireland needing at least a 21-point victory over the winless Scots in the game that followed. Joe Schmidt's side duly delivered, their four-try to one hammering of the home side consigning Scotland to the wooden spoon in a miserable campaign.
It also left England needing to beat France in the final day of the game by a minimum of 26 points, enough to equal the Irish points differential on +63 and beat them on tries scored, having started the day already on 11 tries comapred with Ireland's final total of eight. It was all going to come down to mathematics but first Ireland had to secure victory.
Having paid the price for a slow start in Wales last week when their pursuit of a Grand Slam was ended by conceding four penalties to the boot of Leigh Halfpenny in the first quarter, Ireland this time raced out into a 10-0 lead after 11 minutes. Captain Paul O'Connell led by example with a fourth minute try after picking the ball from a ruck and diving over from short-range. Johnny Sexton added the conversion and then a penalty but Laidlaw got Scotland on the board with a penalty seven minutes later.
Ireland extended their lead further on 24 minutes when Devin Toner won a lineout at the back, and smoothly worked some space to slip the ball to Sean O'Brien, the flanker busting a Dougie Fife tackle to charge over. Sexton converted and Ireland were 17-3 up and cruising.
Scotland, though, had plenty to play for after losing their first four games and already facing the real possibility of a tournament whitewash they sparked into life, fly-half Finn Russell taking advantage of defensive confusion after Ireland had been turned by a Tommy Seymour grubber kick to score a try worked down the left flank.
Laidlaw kicked the conversion but Ireland hit back immediately with a penalty from the restart delivered by Sexton to push the lead to 20-10 but it was Scotland who finished the half strongest.
This was fast-paced open rugby and the home side were contrubiting fully to the spectacle, Matt Scott breaking the line as the Scots threatened but knocking on in contact, the lively Stuart Hogg's pick up and dash over the line in vain as Ireland saw out the half with their 10-point advatange intact.
Clearly the chase for points was still on but Ireland remained patient as the second half got under way, the first breakthrough coming after sustained pressure with Sexton penalty.
There was more to come on 50 minutes when Ireland returned to the Scottish 22, launched a driving maul and from an ensuing ruck, Sexton sent a flat pass to Jared Payne whose straight line sent him under the posts, the conversion from Sexton pushing Ireland into a 30-10 lead.
But just as the fly-half appeared to have rebounded from a poor outing against Wales, Sexton missed two penalties in a row, hitting a post from close range and then sending another, longer kick wide after prop Geoff Cross was sinbinned for a ruck offence.
Sexton got back on track with a penalty during the front-rower's absence but Ireland failed to take further advantage of the power play and it was not until the 72nd minute that the visitors crossed the line again, Sean O'Brien capping a rampaging, man of the match performance with his second crucial score of the afternoon, substitute Ian Madigan, just on for a cramping Sexton, converting to send Ireland into a 40-10 lead.
There was still some fight in Scotland and anxiety for Ireland when Hogg got over the line at the other end but Scottish hopes were crushed further when the video showed the full-back had dropped the ball in contact under Jamie Heaslip's tackle.
One more chance for points came Ireland's way as the clock ran down by Madigan missed a last-minute penalty, referee Jerome Garces whistling for full-time as the focus immediately turned to Twickenham.
SCOTLAND: S Hogg; D Fife (T Visser, 11-23), M Bennett (T Visser, 71), M Scott (G Tonks, 69), T Seymour; F Russell, G Laidlaw – captain (S Hidalgo-Clyne, 57); R Grant (A Dickinson, 32), R Ford (F Brown, 52), E Murray (G Cross, 11); J Hamilton (T Swinson, 52), J Gray; A Ashe, B Cowan, D Denton.
Yellow card: Cross 56-66
Replacement not used: R Harley.
IRELAND: R Kearney; T Bowe, J Payne, R Henshaw, L Fitzgerald; J Sexton (I Madigan, 71), C Murray (E Reddan, 79); C Healy (J McGrath, 54), R Best (S Cronin, 61), M Ross (M Moore, 46); D Toner (I Henderson, 61), P O'Connell – captain; P O'Mahony, S O'Brien (J Murphy, 73), J Heaslip.
Replacement not used: F Jones.
Referee: Jerome Garces (France)