USA and Uruguay are just two of the world's top 20 nations looking to improve their IRB World Ranking points this weekend, but unlike the other 14 in action they also have the small matter of Rugby World Cup 2011 qualification at stake.
The Eagles take a five-point advantage into the second leg of their Americas play-off in Lauderhill, Florida, on Saturday after triumphing 27-22 in Montevideo last weekend to record an 11th win in 12 meetings with Los Teros.
However, the 13 points scored by 21-year-old full back Jerónimo Etcheverry in the last six minutes mean that the Americas 2 spot in Pool C alongside Australia, Ireland, Italy and Europe 2 is still all to play for this weekend.
USA climbed one place to 17th on the back of that first leg victory and would remain in that position even with a victory by more than 15 points, although potentially just over a tenth below Russia.
Los Teros, bidding to return to the Rugby World Cup stage after losing to Portugal by a single point in the Repechage for 2007, will remain 20th regardless of the outcome, with the Eagles falling one or two places in defeat.
The only international taking place outside of Europe this weekend is in the Japanese capital of Tokyo where Canada will look to avenge a 46-8 mauling at the hands of the Brave Blossoms last Sunday.
That emphatic victory saw the sides swop places with Japan assuming a best ever ranking of 13th and John Kirwan's charges must avoid defeat if they are to retain that position. A loss for either side will see them slip closer to Tonga.
If the Japanese can again hand Canada a loss by more than 15 points then they could close to within seven tenths of Italy in 12th, while a loss for either side will see them slip closer to Tonga.
Australia risk new ranking low
Australia were the only side in the top 10 to remain static after last weekend's matches, despite seeing Ireland snatch a 20-20 draw with Brian O'Driscoll's last minute try at Croke Park to end their Grand Slam hopes.
The Wallabies have now moved on to Edinburgh where they will face Scotland, a side they currently enjoy a 16-match winning streak against dating back to 1982. The visitors have won their last seven encounters at Murrayfield.
An emphatic victory along the lines of their 44-15 triumph in their last meeting on Scottish soil will only improve their rating by five tenths, but could condemn their hosts to a one or two place fall depending on Fiji and Samoa's results.
If Scotland can end this losing streak then they could potentially climb one place depending on results elsewhere, with Australia also at risk of a potential three place fall to sixth - their lowest ever position - with a defeat by more than 15 points.
For this to happen it would also need France to beat Samoa at the Stade de France, Ireland to defeat Fiji at the RDS and England to also end a seven-match losing streak against the All Blacks, the latter by a margin of more than 15 points.
England, who climbed two places to sixth with victory over Argentina, could themselves end the weekend in third, although they would need to run riot against the All Blacks and Scotland beat Australia by a similar margin.
All change at the top again?
If England do manage to beat the All Blacks for the first time at Twickenham since 2002 and the Springboks preserve their 100 percent record against Italy, then South Africa will return to the summit of the IRB World Rankings and regain the position they lost with defeat by France in Toulouse.
The world and Tri Nations champions cannot improve their rating of 89.97 this weekend as a result of the 10 places and 18.74 points separating them 12th ranked Italy, who themselves lost 20-6 to a much-changed New Zealand side in Milan.
France - who assumed the mantle of the leading northern hemisphere side by beating South Africa 20-13 - and Ireland also cannot improve their rating points of 83.20 even with comfortable victories in St Denis and Dublin.
However while South Africa cannot slide from second place even with a loss by more than 15 points, France and Ireland could drop one or two places depending on the results at Twickenham and between Wales and Argentina in Cardiff.
Argentina are the only other side who could enjoy a significant climb with a return to the fourth spot they held at the turn of the year with victory over Wales and defeats for France, Ireland and England.
With so many different permutations across the matches in Europe it is entirely possible that the top 10 of the IRB World Rankings could again look very different when they update at 12:00 UK time on Monday.
The only thing that is certain is that the European Nations Cup match between Switzerland and Armenia will not impact the rankings as the latter are not yet a full Member Union of the International Rugby Board and therefore not ranked.