Ireland defeated Wales 17-15 in a game of dramatic and escalating tension at the Millennium Stadium yesterday to win their first Six Nations grand slam since 1948.
Elsewhere, England survived an error-strewn second half to complete a 26-12 victory over Scotland, reclaiming the Calcutta Cup and finishing their Six Nations campaign on a high while France routed Italy 50-8 in Rome.
However, all the attention was focused in Cardiff where flyhalf Ronan O'Gara dropped the winning goal three minutes from time after captain Brian O'Driscoll and right wing Tommy Bowe had scored tries in quick succession to put Ireland 14-6 ahead early in the second half.
Welsh flyhalf Stephen Jones, who kicked the only points of the first half, kept the defending champions in contention with two nerveless penalties and Gavin Henson failed with an ambitious attempt from halfway.
Five minutes from time, Jones brought the home fans in the packed stadium to their feet with a dropped goal which soared between the posts to give Wales a one-point margin and take his tally to 15.
But Ireland were not to be denied. They surged back into the Welsh half, set up the ruck and O'Gara, gesturing frantically for the ball, dropped the most important goal of his illustrious career.
Ireland's army of supporters celebrated joyously after the final whistle.
At Twickenham, a first international try for wing Ugo Monye and a third in two games for impressive centre Riki Flutey helped England to a 15-3 half-time lead after Scotland had briefly threatened in the opening quarter.
In an error-strewn second half, Scotland closed the gap to six points through the goalkicking of Phil Godman and Chris Paterson but a Danny Care drop goal and a late try for Mathew Tait made sure of England's win.
France responded to last week's drubbing in England by running in seven tries to crush sorry Italy in Rome.
Winger Maxime Medard touched down twice and scrumhalf Morgan Parra kicked 15 points to help France claim their third win from five games and remove some of the bitter taste left by the 34-10 defeat at Twickenham.
Captain Sergio Parisse scored a consolation try and fullback Andrea Marcato kicked a penalty for Italy who take the wooden spoon from a dismal winless campaign.