Two tries from Sean O'Brien helped Ireland to a record-equalling victory over Scotland at Murrayfield and ensured they retained their Six Nations title - eventually.
Having seen Wales rout Italy earlier in the afternoon, Ireland knew they needed a win of at least 21 points in Edinburgh. They managed that, and then some, leaving England with a mammoth task in the final match of the Six Nations - a winning margin of 26 points against France at Twickenham.
When England failed to manage that, Ireland fans who had stayed at Murrayfield to watch the game on a big screen celebrated in style, before their team collected the trophy in a floodlit ceremony on the pitch.
There was anticipation in the air as Ireland arrived at Murrayfield hoping that Scotland would not stand in their way of a second successive Six Nations title.
Wales' 61-20 win over Italy in Rome raised the tension as the championship went to the wire and Joe Schmidt's Irishmen knew they would have to pile forward ahead of England's evening clash with France, with points difference looking like it would be required to settle the three-team title race.
Both side's made two changes for the Edinburgh meeting. Scotland head coach benched Alasdair Dickinson and Rob Harley and brought back Ryan Grant and Adam Ashe. The visitors, meanwhile, handed Luke Fitzgerald his first Test start in four years while Cian Healy also came in as Jack McGrath dropped to the ranks of the replacements and Simon Zebo missed out completely.
Wales' Rome triumph meant the Irish needed at least a 21-point win to keep hold of their crown and they wasted little time bulldozing over for a fourth-minute try.
A great break from Tommy Bowe took them to within a yard of the try line. And after the visitors kept the move alive, skipper Paul O'Connell found the room to squeeze round a ruck and finish off the touchdown to become Ireland's oldest ever scorer. Jonathan Sexton added the extras and then a penalty to cement the perfect start.
The Scots had been shell-shocked by Ireland's ferocious opening but eventually got a foothold before putting themselves on the scoreboard when captain Greig Laidlaw knocked over a simple penalty.
But a clever pincer movement between Robbie Henshaw and Luke Fitzgerald almost put Ireland in again before Dougie Fife - back on after a brief spell off the pitch having a wounded tended - came up with a vital tackle.
There was no stopping O'Brien though as he brushed off the winger for the second score after 24 minutes. From a line-out, Devin Toner collected and turned to see the Leinster flanker offer the perfect angle as burst in for his fourth Test try. Sexton again converted.
But the hosts responded in style with eight minutes of the half left. Stuart Hogg pressurised Rob Kearney into dropping a grubber before Seymour drove the Scotland forward further. He was brought down five yards out but Laidlaw moved the ball wide for Russell to gallop round the back and score.
Laidlaw put the conversion over but Ireland clawed some points back with another Sexton kick. Hogg thought he had grabbed another try just before the break but French referee Jerome Garces had already blown up after Matt Scott knocked-on.
The second half was just four minutes old when Jim Hamilton handed Sexton another easy kick just under the posts after failing to role away after a tackle.
And the points continued to be tallied up for Ireland when Sexton opened up a hole in the Scottish defence for Jared Payne to run through with a simple dummy after 49 minutes. The Ulsterman's try was once again converted by Sexton.
However, the Racing Metro fly-half stuck the post with his next penalty attempt. Having conceded twice already this championship from rebounds, the Scots were just grateful the ball bounced their way this time.
But they were not so happy when they were reduced to 14 men. Substitute prop Geoff Cross was sent to the sin-bin for playing the ball illegally at a ruck - but Sexton showed his nerves when he wasted the chance to put Ireland out in front in the championship race as he screwed the penalty wide.
Sexton composed himself for his next effort though and nailed it through the posts to put Ireland on the verge of glory.
Ireland held a 19-point lead over the English but they were desperate for more. From a five-yard line-out they worked through five phases before O'Brien wriggled past Al Dickinson to finish off another crucial try after 71 minutes. Substitute kicker Ian Madigan did the necessary with the conversion.
Irish hearts momentarily skipped a beat when it looked like Stuart Hogg had dived over for the Scots - but the television match official came to the rescue as the full-back's fumble just before grounding the ball was spotted.
Garces handed Schmidt's side a last-minute penalty but Madigan blew the chance to heap more pressure on England when he fluffed it wide. Ultimately, it was still good enough.