Belgium, Germany and Switzerland have secured their places at the 2014 World Cup in Brazil, with Russia almost certain to join them.
Italy and Holland were the only guaranteed European qualifiers heading into Friday's round of fixtures.
The first nation to join them were Belgium after they overcame closest challengers Croatia 2-1 in Zagreb.
The visitors needed only to avoid defeat to be sure of qualifying as winners of Group A, but got across the line with plenty in reserve.
Romelu Lukaku's brace sealed an impressive victory as Croatia - who replied late on through Niko Kranjcar - had to be content with a place in the play-offs.
Switzerland secured their place in Brazil with a comfortable 2-1 away win over Albania.
A draw would have been enough for Ottmar Hitzfeld's side to secure top spot in Group, E but they played for the win and got it with second-half goals from Granit Xhaka and Michael Lang.
There was late drama when Diego Benaglio fouled Odise Roshi in the area and Hamdi Salihi blasted home an 89th-minute penalty, but Switzerland hung on to finish the job off with victory.
Germany beat the Republic of Ireland to secure their spot in Brazil, triumphing 3-0.
Sami Khedira set the ball rolling with a deflected 12th-minute effort from distance, but it was not until Chelsea forward Andre Schurrle converted Toni Kroos' pass from close range 13 minutes after the restart that the points were assured.
Mesut Ozil added extra gloss to the scoreline, striking in stoppage time to top Group C with a game to spare.
Russia are almost certain to join the them after a 4-0 win in Luxembourg on a night in which nearest rivals Portugal could only draw 1-1 with Israel.
Alexander Samedov, Victor Faizulin and Denis Glushakov all scored in the first half for Fabio Capello's side, with Alexander Kerzhakov adding netting the fourth in the 73rd minute.
It will take something remarkable to stop Russia qualifying, as they have a three-point cushion and a far superior goal difference heading into the final Group F match in Azerbaijan.
Portugal look set to be beaten to an automatic ticket to Brazil after Ricardo Costa's strike was cancelled out late on when Israel's Eden Ben Basat capitalised on a poor Rui Patricio giveaway.
Elsewhere this evening, Wales secured a 1-0 win over Macedonia in Group A and, having already won Group B, Italy held Denmark to a 2-2 draw.
Pablo Osvaldo put the visitors ahead, only for Nicklas Bendtner brace to put the hosts ahead in Copenhagen. The Danes were, however, denied victory as Alberto Aquilani netted in stoppage time.
Bulgaria are in second place despite a 2-1 defeat in Armenia, where Aras Ozbiliz and Yura Movsisyan netted. Ivelin Popov scored for Bulgaria, who had Svetoslav Dyakov sent off.
Tomas Hubschman, David Lafata, Vaclav Kadlec and Tomas Pekhart netted for the Czech Republic as they won 4-1 in Malta, for whom Michael Mifsud scored.
In Group C, Zlatan Ibrahimovic's late strike (see above) secured a 2-1 win against Austria and a place in the play-offs.
Martin Harnik put the visitors ahead, only for Martin Olsson and Ibrahimovic to score as a runners-up spot was secured.
The Faroe Islands picked up their first point of qualifying as Hallur Hansson's long-range strike put them on course for a 1-1 draw with Kazakhstan, for whom Andrey Finonchenko levelled.
Holland showed no sings of letting up despite having already secured progression as Group D champions, thrashing Hungary 8-1.
Robin van Persie hit a hat-trick, while there were also goals for Kevin Strootman, Jeremain Lens, Rafael van der Vaart and Arjen Robben.
Szilard Devecseri netted an own goal, while Balazs Dzsudzsak struck home a consolation penalty for Hungary.
There was also a big win for Romania, with Claudiu Keseru, Bogdan Stancu, Gabriel Torje and Costin Lazar scoring in a 4-0 win at Andorra.
They are level on points with Turkey, who won 2-0 in Estonia thanks to goals from Umut Bulut and Burak Yilmaz either side of half-time.
Iceland beat Cyprus 2-0 in Group thanks to Kolbeinn Sigthorsson and Gylfi Sigurdsson goals, while Milivoje Novakovic hit a hat-trick in Slovenia's 3-0 win against Norway.
Rufat Dadashov and Mahir Shukurov helped Azerbaijan to a 2-0 win against Northern Ireland in Group F, while Bosnia-Herzegovina remain top of Group G thanks to a 4-1 win against Liechtenstein.
Edin Dzeko's brace was complemented by Zvjezdan Misimovic and Vedad Ibisevic efforts in the first half, with Nicolas Hasler pulling one back after the break.
Martin Skrtel's own goal earned Greece a 1-0 win over Slovakia, putting them level on points with Bosnia heading into the final game.
Fedor Cernych and Saulius Mikoliunas helped Lithuania beat Latvia 2-0 in the other Group G encounter and England remain top of Group H after beating Montenegro 4-1 at Wembley.
Wayne Rooney and an Branko Boskovic own goal but the hosts ahead, only for Dejan Damjanovic to pull one back. Andros Townsend and Daniel Sturridge ensured there was no comeback.
Ukraine remain hot on their heels after Andriy Yarmolenko's 64th-minute strike earned them a 1-0 win against Poland, while earlier Eugeniu Sidorenco's brace and a Viorel Frunza goal helped Moldova to a 3-0 victory in their qualifier against San Marino.
Finally, Spain need just a point from Tuesday's clash with Georgia to secure their place at the World Cup.
The reigning champions moved clear at the top of Group I after a 2-1 win at home to Belarus, courtesy of goals from Xavi and Alvaro Negredo. Sergei Kornilenko pulled one back for the visitors late on.