Coaches, players and fans in seven countries will rejoice or sigh as their teams join the 14 who have qualfied for next year's finals in Brazil.
Four European teams will clinch their places, two from South America and one from CONCACAF, the North and Central American and Caribbean zone.
Playoff places across all three regions will also be decided.
But qualifying for Brazil is no guarantee of prolonged joy, or job security, as Holger Osieck discovered on Saturday when he was dismissed as Australia's coach despite leading them to their fourth finals last month.
The Australian FA axed him following a 6-0 friendly defeat to France, a month after a 6-0 defeat to Brazil.
That, however, is an exception.
Generally, coaches who cross the finish line first will lead their countries.
This group should include Vicente del Bosque, of world champions Spain, one of four European teams who can confirm their passage on Tuesday.
Only one reigning champion has failed to defend their title since the World Cup began in 1930 - Uruguay, who did not enter in 1934. Spain are unlikely to join them and share that distinction.
But Spain are in a tight two-way battle with 1998 world champions France for the automatic qualifying berth from Group I and will only qualify if they avoid defeat to minnows Georgia, in Albacete.
Spain have 17 points and France 14, but if Spain slip to defeat, France would finish top if they beat Finland by enough goals.
Fabio Capello's Russia would have qualified on Friday if Portugal had lost at home to Israel, but a 4-0 win for the Russians over Luxembourg and Portugal's 1-1 draw with Israel means Group F will not be decided until Tuesday.
Russia have 21 points and Portugal 18. Russia will qualify with a win over Azerbaijan, but if they lose and Paulo Bento's Portugal score heavily in beating Luxembourg, the Portuguese could finish first.
In Group H, England lead with 19 points, one more than Ukraine, and Roy Hodgson's men will qualify with a win over Poland at Wembley.
The Poles may be out of contention in fourth place, but their arrival in London for the group finale is pregnant with memories that have haunted English soccer for 40 years.
Although they have beaten England only once in 18 matches over 47 years, it is the night Poland drew 1-1 at Wembley in October, 1973, that revives nightmares.
That defiant draw carried Poland through, for the first time since 1938, to finish third in the 1974 finals, but eliminated Alf Ramsey's England.
England cannot afford another draw, or defeat, because Ukraine should win well in San Marino.
While England are just one win from their 14th finals, Bosnia will qualify for the first time if they win in Lithuania and force Greece into the playoffs.
The two are level on 22 points at the top of Group G and, with Greece at home to winless Liechtenstein, Bosnia know only a victory will do.
There are plenty of other issues to settle in Europe with nine countries aiming to finish second in their groups.
Only the eight best runners-up will take part in next month's playoffs.
Those striving to qualify by this route include Iceland, who have never been to the finals, but will go into the playoffs as runners-up to Switzerland in Group E if their result in Norway, is equal to, or better than, Slovenia's against the already-qualified Swiss.
Beyond Europe, Ecuador and Chile look set to qualify from the South American zone, joining already-qualified Argentina and Colombia in making the relatively short trip to Brazil.
South American champions Uruguay, in fifth place in the group, look set for a playoff against Asia's fifth best team Jordan next month.
The United States and Costa Rica have alrready qualified from the CONCACAF zone while Honduras look set to seal the third spot on Tuesday, when they visit Jamaica.
That would leave Mexico needing to beat Oceania winners New Zealand to make it to Brazil.