Italy's reward for their Six Nations win over France is a one place jump to ninth in the latest rankings, a position they have not occupied since 2007.
Tries from captain Sergio Parisse and prop Martin Castrogiovanni helped Italy to a 23-18 victory over France at the Stadio Flaminio on Sunday, a result which lifts the Azzurri above Wales.
The defeat was a costly one for France, as they surrender their position as the leading northern hemisphere nation in the rankings with England assuming fourth spot by just over four tenths.
England ran out 38-18 winners over Scotland at Twickenham on Saturday but that result had no impact on their rating, with the Scots remaining in their lowest ever position of 12th after failing to end a 30-year wait for victory over the Auld Enemy at the venue.
Ireland were the other winners in round one, withstanding a Welsh second-half fight-back to win 30-22 at the Millennium Stadium. They remain sixth, just over two rating points behind France and now 3.62 points above Samoa and Argentina below them.
The defeat - their eighth in a row since completing the Grand Slam last March - means Wales equal their lowest ever position in the rankings, one they last occupied after losing to Fiji at RWC 2007.
The opening weekend of the Six Nations, though, was not the only tournament to have an impact on the IRB World Rankings with Division 1A of the European Nations Cup 2014 kicking off as well.
With the Europe 1 and 2 qualifiers for RWC 2015 being determined by this competition, and the six sides ranked between 17th and 22nd in the rankings the matches were expected to be tight and so it proved with six points the biggest margin of victory.
That was secured by Romania, who ran out 19-13 winners over Portugal in Lisbon. That result, in tandem with Russia beating the higher ranked Spain 13-9 in Sochi, means that Romania climb one place to 18th.
Russia also rise one to 19th with Spain falling two places from their highest ever ranking as a result of the defeat. Their Iberian neighbours Portugal slip one place to 23rd with Uruguay the beneficiaries.
The other match pitted Georgia against Division 1A newcomers Belgium in Brussels with the defending champions expected to prove too tough for their hosts.
However, the Lelos needed a 71st minute try from replacement Levan Chilachava to secure the 17-13 victory and close to within two rating points of USA above them.
Belgium remain 21st with the defeat, although now only three tenths above Uruguay.
IRB World Rankings
(Previous position bracketed)
1(1) New Zealand 90.08
2(2) South Africa 86.94
3(3) Australia 86.87
4(5) England 83.90
5(4) France 83.49
6(6) Ireland 81.33
7(7) Samoa 78.71
8(8) Argentina 78.71
9(10) Italy 77.82
10(9) Wales 77.27
With thanks to the IRB