Ireland went into their match with Samoa as the lower ranked of the two teams, but the 40-9 victory at the Aviva Stadium on Saturday means the Irish climb two places to sixth.
The margin of victory was enough to not only lift Ireland above Samoa but also Wales, albeit only by five hundredths of a rating point after the Welsh fell to a 24-15 defeat against South Africa at the Millennium Stadium.
This defeat means Wales have now gone 17 Tests without beating either the Springboks, Wallabies or All Blacks.
The win means South Africa narrow the deficit slightly to New Zealand above them with the All Blacks due to celebrate four years atop the IRB World Rankings on 16 November.
France’s 26-19 defeat by New Zealand has not proven too costly for Les Bleus, who maintain their spot but with a lower rating point total. The All Blacks are again unchallenged at top spot with a slightly improved rating.
Australia remain fourth after the 50-20 win over Italy but improve their total by half a point thanks to the try-fest in Turin.
England and Argentina began the weekend third and 10th respectively in the world and are unchanged despite the home side’s 31-12 victory at Twickenham.
Scotland stay ninth after their 42-17 win over Japan, but with an improved points rating, and the vanquished Brave Blossoms rise one place to 14th as a result of Canada's 19-15 loss to Georgia in Tbilisi.
Portugal hosted Fiji in Lisbon but endured a try count of six to one as the visitors ran up a 36-13 result to climb one place to 12th with the Portuguese remaining 22nd.
Tonga fall two places to 13th after a last minute penalty by Florin Vlaicu secured a 19-18 win for the 17th ranked Romanians in Bucharest, a result which benefits Italy who, despite the loss to the Wallabies, rise a place to 11th
The wins over higher ranked opponents did not result in positional gains for Georgia or Romania, but they improved their ratings by 1.2 and 1,56 points respectively. Canada, though, fall one place to 15th.
Their fellow North Americans were in action with the USA losing 29-19 to the Maori All Blacks, but only matches between the national teams of two IRB Full Member Unions count towards the rankings.
Namibia stay 23rd after their 35-26 win over Zimbabwe in the opening match of the Tri Nations Rugby Series in Windhoek - a tournament which also features Kenya - while the losing side do rise one place to 32nd as a result of Poland's heavy loss to Germany in the European Nations Cup.
Two other African sides in action - albeit on neutral soil in France - were the Ivory Coast and Senegal. The Ivory Coast were ranked six places higher going into the match in 42nd, but the 33-10 defeat means they have drop six places to 48th with Senegal rising seven places to 41st.
Chile also fall one place to 27th after suffering a 26-3 defeat against Spain in Santiago, a result which helps the Spanish consolidate their place in the world’s top 20.
There was plenty of European Nations Cup action over the weekend, with Germany overcoming Poland 43-14 in Division 1B to remain on top of the standings and also climb one place in the IRB World Rankings to 26th, swapping places with Chile.
The Division 1B winner will meet the Netherlands in a Rugby World Cup 2015 play-off next year for the right to play the Division 1A third place team for a place in the Repechage. The weekend's other match in Division 1B saw Moldova beat Sweden 50-20, a result which left the Moldovans 29th and condemned their opponents to a one place fall to 42nd.
In Division 2A Malta accounted for Croatia 37-18 and the Netherlands beat Lithuania 34-25. Malta climb two places to 43rd as a result and Croatia drop one place to 56th, while the Dutch and Lithuanians are unchanged at 30th and 52nd respectively.
Cyprus were also winners, 34-3 win over Slovenia in Division 2C, but this has no impact on the IRB World Rankings because Cyprus are not a Full Member Union of the International Rugby Board.
Division 2D side Luxembourg were the big losers in ranking terms, their 24-12 defeat at home by Bosnia & Herzegovina sending them eight places down the ladder to 93rd and lifting their conquerors three rungs to 90th.