Three teams are leading the pack in a tough Group A – Belgium, Serbia and Croatia.
Serbia thumped Wales 6-1 in Novi Sad, with Aleksandar Kolarov and Zoran Tosic giving the hosts an early 2-0 lead before Gareth Bale netted from a free-kick.
But further goals from Filip Djuricic, Dusan Tadic, Branislav Ivanovic and Miralem Sulejmani handed the Welsh their heaviest defeat in 16 years.
In Brussels, Guillaume Gillet cancelled out Ivan Perisic’s opener as Belgium and Croatia drew, while Kenny Miller scored to secure a 1-1 draw for Scotland against Macedonia in Glasgow.
Italy were far from impressive in securing a 2-0 win over Malta in Modena, and had Mattia Destro and Federico Peluso to thanks for the three points.
It leaves them on four points alongside Bulgaria, whose 1-0 win against Armenia was marred by three red cards. Stanislav Manolev netted the decisive goal.
Marco Reus and Mesut Ozil were the scorers as Germany maintained their 100 per cent start to Group C, beating Austria 2-1. Zlatko Junuzovic got the consolation for the home side.
Also in the group, Sweden beat Kazakhstan 2-0 thanks to strikes by Rasmus Elm and Marcus Berg.
Holland are showing signs of recovering from their nightmare Euro 2012 campaign, beating Hungary 4-1.
Jeremain Lens gave the Dutch before Balazs Dzsudzsak equalised from the spot, but Martins Indi, another Lens effort and Klaas-Jan Huntelaar secured the points.
Romania kept up the pressure though, with Gabriel Torje, Costin Lazar, Valerica Gaman and Alexandru Maxim scoring in a 4-0 win over Andorra.
Also in the group, Turkey beat 10-man Estonia 3-0 as Emre Belozoglu, Umut Bulut and Selcuk Inan found the back of the net.
Xherdan Shaqiri and a Gokhan Inler scored as Switzerland beat Albania 2-0 to lead Group E.
Elsewhere, John Arne Riise netted a last-minute penalty as Norway came from behind for a 2-1 win against Slovenia. Marko Suler scored the opener, but Markus Henriksen equalised before Riise showed his nerves of steel.
Meanwhile, Konstantinos Makridis scored the only goal of the game as Cyprus beat Iceland.
Portugal and Russia lead the group, with the Portuguese beating Azerbaijan thanks to second-half goals from Silvestre Varela, Helder Postiga and Bruno Alves.
Russia were impressive in their 4-0 defeat of Israel, with Alexander Kerzhakov’s brace and further goals from Aleksandr Kokorin and Viktor Faitzulin ensuring an easy three points.
The other game in the group saw Northern Ireland only manage a 1-1 home draw against Luxembourg.
Bosnia-Herzegovina came from a goal down to beat Latvia 4-1, with Zvjezdan Misimovic getting a brace and Miralem Pjanic and Edin Dzeko the others.
The top the table along with Greece, who had Sotiris Ninis and Kostas Mitroglou to thank for their 2-0 win against Lithuania.
In the group’s other game, Slovakia beat Liechtenstein 2-0 courtesy of Marek Sapara and Martin Jakubko’s goals.
England were held to a 1-1 draw at home by Ukraine, who took the lead just before the break courtesy of Yehven Konoplyanka’s cracker.
Roy Hodgson’s men equalised near the end through Frank Lampard’s penalty, after which captain Steven Gerrad was sent off for a second bookable offence.
Poland joined England at the top of the group after a 2-0 win against Moldova - Jakub Blaszczykowski and Jakub Wawrzyniak scoring the goals.
Also top of the group is Montenegro, who thumped whipping boys San Marino 6-0. Fatos Beqiraj and Andrija Delibasic each got a brace, while Luka Djordjevic and Elsad Zverotic netted the others.
Reigning world and European champions Spain needed a late strike from Valencia hitman Roberto Soldado to get past a spirited Georgian side in Tbilisi.
The Spanish are currently second in the group behind Italy, who cruised to a 3-1 win over Belarus in Paris.
Etienne Capoue, Christophe Jallet and Franck Ribery netted for Didier Deschamps side, with Anton Putsila getting the goal for the visitors.