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 reigning Six Nations champions fell to a 24-15 defeat to South Africa in Cardiff.
This latest loss 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 - Ireland's final opponents in the GUINNESS Series this month - due to celebrate four years at the top of the IRB World Rankings on November 16.
France's 26-19 defeat by New Zealand has not proven too costly for les Bleus, who maintain their fifth place ranking, but with a lower rating points total. The All Blacks are again unchallenged at the summit with a slightly improved rating.
Australia, who meet Ireland next Saturday evening, 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.
IRB WORLD RANKINGS (as of Monday, November 11):
Last week's positions in brackets -
1(1) New Zealand 93.20 rating points
2(2) South Africa 88.51
3(3) England 86.31
4(4) Australia 84.22
5(5) France 81.44
6(8) IRELAND 80.76
7(6) Wales 80.71
8(7) Samoa 79.24
9(9) Scotland 77.25
10(10) Argentina 75.50
11(12) Italy 73.65
12(13) Fiji 73.56