England are there - and so are holders Germany - but there were mixed fortunes for some of the other home nations in their quest to qualify for next summer's World Cup finals in Russia.
Wales can still win their group and Northern Ireland are guaranteed a play-off spot but Scotland fell short, finishing fourth in Group D after drawing their crunch final game in Slovenia.
Meanwhile, three-time runners up the Netherlands are all but out, Argentina are in trouble and Syria are in a play-off to keep their unlikely World Cup dream alive.
Here, we analyse the scenarios to establish who needs what as qualifying reaches its climax. Bear with us - it's complicated, but worth it.
Who has qualified?
The tournament will consist of 32 teams, with hosts Russia joined by 31 qualifiers from around the globe.
The holders no longer qualify automatically, but Germany have progressed as group winners with a 100% winning record in Group C.
There are 13 other sides guaranteed to be there: Brazil, Iran, Japan, Mexico, Costa Rica, Belgium, Saudi Arabia, South Korea, Spain, England, Nigeria, Poland and Egypt.
In Europe, the side that top each of the nine groups reaches the finals, while the best eight of nine runners-up go into November's play-offs.
What about the home nations?
Northern Ireland
Scotland's draw in Slovenia means that Northern Ireland are guaranteed a play-off place as one of the eight best-performing group runners-up.
Michael O'Neill's side lost their final game as Chris Brunt's own goal in the second half gave Norway victory in Oslo but still finished second with 19 points, four ahead of third-placed Czech Republic.
Northern Ireland are looking to reach their first World Cup since 1986.

Wales
Monday: Republic of Ireland (h) 19:45
"Don't take me home, please don't take me home," sang the fans as Walesmarched to the semi-finals of Euro 2016.
Now they want to cheer them in a second World Cup, with their only previous finals appearance coming in 1958.
On Friday, Wales won in Georgia, but the Republic of Ireland also picked up three points to set up a huge meeting on Monday between the sides.
The winners in Cardiff will finish at least second, with a draw enough for Wales.

Leaders Serbia lost on Friday night to a last-minute Austria goal, meaning either Wales or the Republic could earn automatic qualification if Serbia slip up. It's all up for grabs.
Serbia host Georgia on Monday and require a win to be certain of reaching their second finals.
England
Unbeaten England, with eight wins and two draws, qualified automatically, despite following up Thursday's lacklustre 1-0 victory over Slovenia with an equally disappointing one-goal success in Lithuania on Sunday.
Russia 2018 will be England's fifth successive appearance at a major tournament, since failing to qualify for Euro 2008.
Their best performance in that time was reaching the last eight at the 2012 European Championships in Poland and Ukraine.
Scotland
There was heartbreak for Scotland in Slovenia.
It was all going to plan when Leigh Griffiths gave them the lead in the first half, but two goals from Roman Bezjak meant that not even Robert Snodgrass' late leveller could rescue their qualification bid.
With only four points from their first four matches, few were rushing to back Scotland to reach Russia and seal a first World Cup appearance since 1998.
And so it proved, despite them claiming 14 points from their last five games.

The play-off puzzle
There's no easy way of explaining this, but here goes...
Eight of the nine European runners-up go into a two-legged play off for four places at next year's finals. That means the runner-up with the fewest points misses out.
It is important to note that results against the bottom side in each group do not count in the final play-off standings.
Therefore Slovakia, who are seventh, did not improve their points tally in the final round of games with their 3-0 win over Malta. They can be overtaken by the two sides below them - Wales and Croatia.
The ranking of second-placed teams in the qualifying groups is determined by the highest number of points. If teams are equal on points, positions are decided by goal difference, goals scored, goals scored away from home and fair play points.
Fifa says teams will be seeded for the draw on 17 October, with the top four sides according to its rankings at the time in one pot and the remaining four in another.
The teams currently in second place are Portugal (third in rankings), Wales (13), Italy (17), Croatia (18), Slovakia (19), Northern Ireland (20), Sweden (23), Denmark (26) and Greece (47).
While there are clearly plenty of permutations, Northern Ireland and/or Wales could be seeded.
In the below table, teams in bold are certain to be in the play-offs.
Play-off table as it stands |
Position/Team |
Played |
Goal difference |
Goals scored |
Pts |
1 Portugal |
7 |
+18 |
22 |
18 |
2 Denmark |
8 |
+7 |
13 |
14 |
3 Italy |
7 |
+3 |
11 |
14 |
4 Sweden |
7 |
+10 |
17 |
13 |
5 Northern Ireland |
8 |
+4 |
10 |
13 |
6 Greece |
8 |
+4 |
9 |
13 |
7 Slovakia |
8 |
+5 |
10 |
12 |
8 Wales |
7 |
+2 |
7 |
11 |
9 Croatia |
7 |
+2 |
6 |
11 |
Wales and the Republic of Ireland can secure second place in Group D but both could still potentially be out of luck, as they can all still finish ninth in this table.
Rest of Europe - Netherlands set to miss out
Europe's places: 14 including hosts Russia. Already qualified: Belgium, Russia, Germany, England, Spain, Poland.
They may be three-times World Cup runners-up but the Netherlands' hopes of reaching next year's tournament are as good as over.
The Dutch are in third place in Group A, behind France and Sweden, and they need to beat Sweden by an improbable seven goals on Tuesday in order to reach the play-offs.
Surprise Euro 2016 quarter-finalists Iceland, the smallest nation to qualify for a major tournament when they reached Euro 2016, are in pole position to win Group I after a fine win in Turkey on Friday night.
Portugal, while sure of at least making the play-offs, face a critical final match at home to Group B leaders Switzerland on Tuesday as they aim to make up a three-point deficit.
Road to Russia: The key dates
- 17 October: Europe play-off draw (Zurich)
- 9-11 November: Play-off first legs
- 12-14 November: Play-off second legs
- 1 December: Groups are drawn
- 14 June - 15 July 2018: World Cup
Asia - The Syria story

Syria players celebrate after a 2-2 draw with Iran secured a play-off against Australia
Asian places: 4 (plus a play-off place). Already qualified: Iran, South Korea, Japan, Saudi Arabia
Now this is some tale.
Syria remain in contention for the World Cup despite the odds being stacked against a nation that is in the midst of a six-year war.
The team have no funding because of sanctions and play their home games in Malaysia, a 9,000-mile round trip.
But they made it through to a play-off against Australia, with Omar Al Somah's late penalty earning them a 1-1 first-leg draw on Thursday.
The return leg takes place in Sydney on Tuesday, 10 October (kick-off 10:00 BST).
The winner will face a Concacaf (North and Central America and the Caribbean) side in another two-legged tie the following month for a place at the World Cup.
South America - Argentina in trouble
South America places: 4 (plus a play-off place). Already qualified: Brazil
Wednesday 00:30: Ecuador v Argentina, Brazil v Chile, Peru v Colombia, Uruguay v Bolivia, Paraguay v Venezuela

Argentina have lost one and drawn three of their past four qualifying matches
It seems almost inconceivable that Lionel Messi will not be at football's biggest tournament, but his Argentina side are in serious danger of missing out.
The two-time champions, who have not missed the World Cup since 1970, are out of the group qualifying spots after a 0-0 draw with Peru on Thursday.
Only the top four in South American qualifying are guaranteed a place in Russia - and Argentina are sixth with one game left.
Argentina must win their final qualifier in Ecuador to claim at least fifth spot, which sets up a two-leg play-off against New Zealand.

Beaten finalists at the 2014 World Cup, Argentina are level on both points (25) and goal difference (+1) with fifth-placed Peru, who are ahead on goals scored.
So tight is the group that four points separate Uruguay in second (28) and Paraguay (24) in seventh and a win for Argentina could see them qualify automatically.
However, they have drawn their past three qualifiers and their recent record in Ecuadorian capital Quito, which is 2,900m above sea level, is poor, losing two out of their past three and drawing the other. Ecuador have lost their previous five qualifying games.
Peru are hosting fourth-placed Colombia and should they draw, Argentina would be eliminated if they did not win.
Chile, who are third, go to already-qualified Brazil, while Uruguay, who are all-but assured of their place in Russia because of their vastly superior goal difference, need just a draw at home to already-eliminated Bolivia to guarantee qualification.
South American World Cup qualifying: Fixtures - Tables
Concacaf - Who will join Mexico?
North America, Central America and Caribbean places: 3 (plus a play-off place). Already qualified: Mexico, Costa Rica
Mexico will compete at their seventh straight World Cup next summer having already qualified from the Concacaf section, with 2014 World Cup quarter-finalists Costa Rica joining them following a 1-1 draw at home to Honduras on Saturday.
But a third automatic berth is still up for grabs, while the fourth-placed side can also qualify through the inter-continental play-offs.
On Friday night, USA beat surprise package Panama 4-0 to move into third and within touching distance of automatic qualification.
They travel to bottom of the table Trinidad and Tobago on Wednesday knowing victory will seal their spot.
Panama now look destined for a play-off match against either Syria or Australia to land a World Cup place for the first time in their history.
Honduras, whose match in Costa Rica was put back a day because of Hurricane Nate, also remain in the mix. They could still seal an automatic berth though it would need them to beat group winners Mexico and for both USA and Panama to lose their final games.
- North America, Central America and Caribbean World Cup qualifying: Fixtures - Tables
Africa - Nigeria secure their place

Egypt qualified for the World Cup finals for the first time since 1990
African places: 5. Already qualified: Nigeria, Egpyt
Nigeria secured a sixth World Cup appearance with a 1-0 win over Zambia, while Liverpool's Mohamed Salah struck an injury-time winner as Egpyt defeated Congo to reach the tournament for the first time since 1990, but Africa Cup of Nations champions Cameroon are out of the running.
There are no play-offs in Africa, with the team that top each of the five qualifying groups going through. Tunisia, Morocco and Senegal are the other current group leaders.
Oceania - New Zealand await opponents
Oceania places: One play-off place. Already qualified: None
New Zealand beat the Solomon Islands over two legs (as winners of their respective groups) to book their place in the inter-continental play-offs, and will take on the fifth-placed team from South American qualifying in November.