Ireland, though, did have to endure a nervous end to the Millennium Stadium encounter as Stephen Jones' penalty dropped just short with the final act of the match, but the win means they remain the leading northern hemisphere nation in the rankings.
Despite the Grand Slam success Ireland still trail Australia by 2.59 rating points, although they do now have a cushion of 1.71 points from Argentina, who climb one place to fifth as a result of Wales' two place fall to seventh in defeat.
England are the other beneficiaries, climbing one place to sixth after regaining the Calcutta Cup with a 26-12 defeat of Scotland at Twickenham, a victory which sees them finish second on points differential from France and Wales in the Six Nations standings.
France bounced back from their defeat by England the previous weekend with a 50-8 victory over Italy, although the seven-try performance in the Stadio Flaminio wasn't enough to alter their position of eighth, while the Italians stay 12th.
There was one further change in the top 10 with Scotland, who finished fifth in the standings after only one victory over Italy, sliding one place to 10th with Fiji reclaiming ninth spot by the smallest of margins, one hundredth of a rating point.
IRB World Rankings - 23 March 2009
1(1) NEW ZEALAND 92.68
2(2) SOUTH AFRICA 89.45
3(3) AUSTRALIA 85.86
4(4) IRELAND 83.27
5(6) ARGENTINA 81.56
6(7) ENGLAND 80.96
7(5) WALES 80.59
8(8) FRANCE 79.94
9(10) FIJI 75.24
10(9) SCOTLAND 75.23