Germany, Switzerland and Belgium booked their place in the 2014 World Cup in Brazil, while England took a huge step towards that goal with an emphatic win over Montenegro.
World and European champions Spain were far from their best, but just about managed a 2-1 victory over Group I bottom side Belarus.
In Zagreb, the talented and exciting Belgium side did not let their fans down, as a Romelu Lukaku double spurred them to a 2-1 win over Croatia, who will now have to settle for second place in Group A.
Lukaku opened the scoring off a nice through ball from Steven Defour, before doing all the work himself, running from the halfway line to dink it over the goalkeeper as Belgium went into the break with a 2-0 lead.
Croatia pulled one back, but wild celebrations were cued from the Belgium faithful as the referee blew the final whistle to confirm the talented side's place in the World Cup in Brazil next year.
"I'm super happy for the team," two-goal hero Lukaku said. "We always believed we could qualify and now it's here."
The final game is academic for Belgium, but there will be a party atmosphere in Brussels on Tuesday when they host Wales.
Arsenal superstar Mesut Ozil was on the scoresheet for Germany, planting the final nail in Ireland's coffin as the perennial World Cup side eased to a 3-0 win.
Sami Khedira opened the scoring for Joachim Low's side before Chelsea forward Andre Schurrle netted the second on the 58th minute. Ozil rounded off the scoring to add the icing on the World Cup-sized cake.
Zlatan Ibrahimovic was the savior for Sweden with the PSG striker scoring a late winner to hand his side a 2-1 win over Austria. The result means Sweden will finish second behind Germany and seal a playoff spot.
Spain grabbed the edge over France in Group I with an unconvincing win over Belarus, courtesy goals from Xavi Henandez and Alvaro Negredo.
The win saw the world champs move three points ahead of France, and Spain will qualify for the World Cup if they pick up a point against Georgia in Albacete.
France, who warmed up for the final round of matches with a 6-0 thumping of Australia in a friendly, have already secured second place and will hope for some divine intervention in the Spain game to help them qualify automatically.
Group H is now in England's control following an impressive 4-1 win over Montenegro at Wembley, with Tottengham winger Andros Townsend starring for the Three Lions.
Wayne Rooney opened the scoring for England four minutes into the second half after a frustrating first period for the hosts. A Branko Boskovic own goal gave England a 2-0 lead, before Dejan Damjanovic reduced the deficit in the 72nd minute.
However, Townsend settled nerves with a brilliant solo goal before Daniel Sturridge added the gloss late on from the penalty spot.
England lead the group by one point from Ukraine, who beat Poland 1-0. Roy Hodgson's men will qualify automatically if they beat Poland in the final qualifier at Wembley on Tuesday.
In Group F, a late blunder from goalkeeper Rui Patricio saw Portugal only draw against Israel 1-1, which left the door open for Russia to qualify top of the group.
Russia now just need a point against Azerbaijan in their final game, after easing past Luxembourg, while Cristiano Ronaldo and Portugal are staring at the playoffs yet again.
The easiest group in Europe - Group E - saw Switzerland book their spot with a 2-1 victory over Albania - Xherdan Shaqiri and Michael Lang scoring the vital goals.
The fight for the second spot is between Iceland and Slovenia, after both sides picked up all three points on Friday. Iceland are in pole position and have their destiny in their own hands, with a victory over Norway on Tuesday enough to ensure second place.
Netherlands, already qualified from Group B, thumped Hungary 8-1 with Robin Van Persie scoring a hat-trick to become the all-time record Dutch scorer. Turkey and Romania, each on 16 points, and Hungary, on 14 points, will fight it out for the second spot.