The big game of the day was the clash between Croatia and Serbia, both former nations of the Yugoslav Republic. Mario Mandzukic and Ivica Olic ensured that it was Croatia who emerged victorious, by way of a 2-0 scoreline.
Belgium also continued their excellent qualifying campaign with a 2-0 win in Macedonia, and in the Great Britain derby, Wales came from behind to beat Scotland, 2-1. Both sides had a man sent off.
Those results leave Belgium and Croatia level on 13 points at the top, with a seven-point gap to Wales in third.
Bulgaria closed the gap at the top to just one point, though they have played a game more than Italy, with a comprehensive 6-0 crushing of Malta, with Aleksandar Tonev hitting a hat trick. In the only other game in the group, Denmark scored three second-half goals to pick up a fine 3-0 win in the Czech Republic.
That result moves Denmark above Czech Rep. into third, though they are four points behind Bulgaria with a game in hand.
Group 3 remains tight after Friday's series of results, which saw leaders Germany pick up a 3-0 win in Kazakhstan. Sweden were held, 0-0, at home by the Republic of Ireland, who remain one point behind the Swedes.
Austria were the biggest winners of the day in the group, routing the Faroe Islands by a 6-0 scoreline, with Philipp Hosiner scoring twice.
Germany remain top on 13 points, but they have played a game more than all three teams chasing them—with Sweden, Austria and Ireland on eight, seven and seven points, respectively.
Netherlands are looking good for qualification for the 2014 World Cup after completing a routine 3-0 win over Estonia, leaving them with five wins from five so far.
The two teams chasing the Dutch, Hungary and Romania, fought out a 2-2 draw after Romania snatched a last-minute equaliser through Alexandru Chipciu. Turkey also played against Andorra and won, 2-0.
Hungary and Romania remain second and third, respectively, tied on 10 points and pushing hard for that playoff place behind Netherlands.
This group continues to progress intriguingly, with the unlikely challenges for group glory coming from Albania and Iceland.
With group-leaders Switzerland not in competitive action this time, it was a chance for both sides to close the gap at the top. Both nations did so in style, Albania winning, 1-0, in Norway and Iceland victorious away to Slovenia, by 2-1 thanks to a Gylfi Sigurdsson brace.
Both winning nations move to nine points, one behind Switzerland, who have a game in hand. Norway are down to fourth, on seven points.
Portugal have struggled to assert their authority and quality in Group 6 and it proved a similar story this time around as they drew, 3-3, against Israel, needing two late goals to come from behind and win a point.
Luxembourg and Azerbaijan missed out on the chance to secure a rare competitive win as they fought out a 0-0 draw. They remain the bottom two clubs in the group, with Israel second, ahead of Portugal on goal difference. Russia top the group by four points with one game in hand.
Six teams in action in Group 7 but only one winner, as Bosnia-Herzegovina beat Greece, 3-1, to move top of the group by three points. Edin Dzeko scored twice for Bosnia.
Liechtenstein and Latvia drew, 1-1, while Slovakia and Lithuania fought out the same scoreline. Greece remain second in the group, with Slovakia third place on eight points—two behind Greece.
England were the biggest winners of the match-day in Europe, trouncing San Marino by an 8-0 scoreline. Seven different England players got on the scoresheet, as well as an own goal. Jermain Defoe was the only player to score twice.
Elsewhere, Montenegro went down to 10 men but secured a 1-0 win away to Moldova thanks to a 79th-minute Mirko Vucinic goal. Ukraine also picked up their first win by beating Poland, 3-1.
All that means first and second place in the group go head-to-head during the week, as England visit Montenegro, with two points between them and Montenegro leading.
There was a shock result in Group 9 as Finland held reigning world and European champions Spain at home, 1-1. The only other game in the group saw France easily beat Georgia, 3-1.
Those results see France move to the top of the group ahead of their game against Spain on Tuesday, with the Spaniards in second place. Both teams remain unbeaten so far.