European qualifying for the 2018 World Cup in Russia is at the halfway stage.
Here's the state of play in the nine groups heading into the sixth round of games from Friday to Sunday:
France can increase its lead to six points with a win in Sweden on Friday.
Without Zlatan Ibrahimovic, Sweden has less individual threat but a greater sense of teamwork. Still, its defense faces a stern test against a side boosted by a recent 5-0 home win over Paraguay. France striker Olivier Giroud has five goals in his last three internationals.
If Sweden loses, Bulgaria can move up to second place by beating Belarus. The Netherlands, in fourth place, hosts last-place Luxembourg.
Switzerland will be looking for a sixth straight win and to keep ahead of Portugal when it plays at the Faeroe Islands on Friday.
Cristiano Ronaldo and Pepe arrived late to Portugal's squad following Real Madrid's win in the Champions League final last weekend, but they should start at next-to-last Latvia.
Portugal, which trails Switzerland by three points, is coming off four straight victories since the opening 2-0 loss against the Swiss.
Last-place Andorra hosts third-place Hungary, which is five points behind Portugal.
World champion Germany should have little difficultly making it six wins from six matches, even though an understrength team will host San Marino in Nuremberg on Saturday.
Germany coach Joachim Loew has given nearly all of his regulars the summer off, but even an unfamiliar looking German lineup should be too much for a microstate with a population more than 100 times smaller than Berlin's.
The Germans have already scored 20 goals in qualifying, conceding only one.
Germany leads with 15 points. Northern Ireland (10 points), the Czech Republic (8), and Azerbaijan (7) all maintain hopes of the runner-up spot and a possible playoff place.
Azerbaijan hosts Ireland in Baku, and Norway hosts the Czechs in Oslo.
The chances of Gareth Bale playing at the World Cup will reduce even further if Wales loses to Serbia on Sunday in the biggest game in the group.
The Welsh are in third place, four points behind Serbia and Ireland, after drawing four of their first five qualifiers and failing to reproduce their form from last year's European Championship, where they reached the semifinals.
Ireland hosts Austria, while Moldova hosts Georgia in a game between two teams already out of contention.
Poland striker Robert Lewandowski, who missed out on being the Bundesliga's top scorer this season, will look to score in his 11th straight European qualifier in a match against Romania in Warsaw on Saturday.
Poland, with 13 points, comfortably leads the group with the others jostling for the runner-up spot, led by Montenegro and Denmark (both with seven points). Romania and Armenia have six.
Denmark, which drew with Germany in a friendly on Tuesday, travels to last-place Kazakhstan, and Montenegro hosts Armenia in Podgorica.
England takes a four-point lead to Scotland for the latest edition of the world's oldest international rivalry, 145 years after their first meeting.
Now under coach Gareth Southgate, England has dropped only two points in five games and would pile the pressure on under-fire Scotland coach Gordon Strachan with a fifth win in qualifying.
Second-place Slovakia visits Lithuania and Slovenia, a further point back in third, hosts Malta.
Italy hosts last-place Liechtenstein on Sunday with a chance to improve its goal difference and move closer to leader Spain, which plays at Macedonia.
Liechtenstein has conceded 19 goals in five matches, including eight against Spain. Italy and Spain have 13 points each from five matches.
Italy is coming off a 3-0 win over Uruguay in a friendly on Wednesday, while Spain was held by Colombia to a 2-2 draw.
Third-place Israel, which is four points behind the leaders, hosts Albania.
Friday could be a big day for Belgium on the road to Russia.
Following a 2-1 win over the Czech Republic in a friendly this week, Belgium is a huge favorite to beat 98th-ranked Estonia and reinforce first place. It currently has a two-point lead.
At the same time as the game in Tallinn, Belgium's closest challenger, Greece, will be in Bosnia-Herzegovina in a game that could be vital in the race for second place and a playoff spot.
The third game, Gibraltar against Cyprus, has no impact on the group.
Belgium has such a wealth of talent that winger Eden Hazard's absence because of a broken ankle should have no impact on its creative play. If anything, it should allow Yuri Tielemans, recently picked up from Anderlecht by Monaco, to flaunt his skills.
It looks to be a straight fight between Croatia and Iceland for top spot and the countries meet in Reykjavik on Sunday.
Croatia leads Iceland by three points with five games left.
Ukraine and Turkey are two points further back and face away games against Finland and Kosovo, respectively.