Ireland's five-try success over the Scots has boosted their rating points from 78.30 to 78.81 and a win over Wales next time out could see them vault into the world's top six again.
In ending France's Grand Slam hopes, England have swapped places with Australia in the rankings and moved up to fourth - the position they lost after they were beaten by Wales in their Six Nations opener.
England are the leading Northern Hemisphere side in the rankings, behind World Cup holders South Africa, New Zealand and Argentina - although they still trail the Pumas by 2.46 rating points.
Wales scored a handsome 47-8 win over Italy on Saturday but the result has not effected their ranking position of eighth. They are, however, now sitting on 77.27 rating points - 1.54 points behind Ireland ahead of the sides' crunch Croke Park clash on Saturday week.
Indeed, the Welsh are the most improved team in the rankings since the start of 2008, courtesy of their three successive victories under new coach Warren Gatland.
Meanwhile, those losses for Scotland and Italy see them remain tenth and eleventh respectively, sandwiched between Rugby World Cup quarter-finalists Fiji and Samoa.
LATEST IRB WORLD RANKINGS (AS OF FEBRUARY 25, 2008):
1(1) South Africa 90.81 rating points
2(2) New Zealand 89.59
3(3) Argentina 87.42
4(5) England 84.96
5(4) Australia 84.20
6(6) France 81.00
7(7) IRELAND 78.81
8(8) Wales 77.27
9(9) Fiji 75.88
10(10) Scotland 74.19
11(11) Italy 72.52