Portugal got their World Cup qualifying campaign off to a shaky start after going down 2-0 to Switzerland in their Group B opener at St Jakob-Park on Tuesday night.
The Euro 2016 champions failed to recover following two first-half goals from Breel Embolo (23') and Admir Mehmedi (30'), although the Swiss finished the game with 10 men after Granit Xhaka was sent off in stoppage time for two bookable offences.
Euro 2016 finalists France also made a less than impressive start in Group A after being held to a 0-0 draw by Belarus at the Borisov Arena, while Hungary had to settle for the same scoreline in their opening Group B clash with the Faroe Islands at Torsvollur.
Elsewhere, Roberto Martinez started his tenure as Belgium head coach on a positive note after his side recorded a comfortable 3-0 win over Cyprus at the GSP Stadium.
Romelu Lukaku opened the scoring after just 13 minutes in Nicosia before adding a second on 61 minutes, with Yannick Carrasco wrapping up the three points nine minutes from time.
The Netherlands had to come from behind to secure a share of the spoils against Sweden as their Group A opener at the Friends Arena ended in a 1-1 draw.
The hosts took the lead through Marcus Berg two minutes before the break, but the Oranje responded with an equaliser from Wesley Sneijder with 23 minutes to go.
Meanwhile, Bulgaria edged Luxembourg in a seven-goal thriller at the Vasil Levski National Stadium to move top of Group A in World Cup qualifying.
The lead exchanged hands numerous times, with Dimitar Rangelov (16') opening the scoring for the Lions, before a brace from Aurelien Joachim (60', 62') put the visitors in front.
After Marcelinho had equalised on 65 minutes, Ivelin Popov restored the Bulgarians' lead with 11 minutes remaining but there was more drama to come as Florian Bohner drew the Red Lions level in stoppage time only for Aleksandar Tonev to grab the winner moments later.
Bosnia-Herzegovina made a flying start to their World Cup qualifying campaign after hammering Estonia 5-0 at the Bilino Polje Stadium.
Emir Spahic broke the deadlock after just seven minutes and he completed the rout in stoppage time, with further goals in between from Edin Dzeko (23' pen), Haris Medunjanin (71') and Vedad Ibisevic (83') securing a handsome win for the Dragons, who moved to the head of Group H.
Greece also recorded a big win in their Group H opener after thrashing Gibraltar 4-1 at Estadio Algarve, with all five goals coming in the first half.
Kostas Mitroglou gave Ethniki the lead after 10 minutes, but the hosts hit back through Liam Walker 16 minutes later. An own-goal from Scott Wiseman in the final minute of the opening stanza restored the visitors' lead before Konstantinos Fortounis and Vasileios Torosidis struck in quick succession to put the result beyond doubt.
Latvia picked up a precious 1-0 victory over Andorra, with Velerijs Sabala netting the winner three minutes into the second half at Estadi Nacional, while earlier in the evening Albania edged Macedonia 2-1 at the Loro Borici Stadium.
The Eagles went in front through Armando Sadiku after just 10 minutes, but Ezgjan Alioski restored parity six minutes into the second half to seemingly earn a draw before Bekim Balaj popped up with a winner in the final minute.
European World Cup qualifying results:
Albania 2-1 Macedonia
Belarus 0-0 France
Bulgaria 4-3 Luxembourg
Sweden 1-1 Netherlands
Andorra 0-1 Latvia
Faroe Islands 0-0 Hungary
Switzerland 2-0 Portugal
Bosnia-Herzegovina 5-0 Estonia
Cyprus 0-3 Belgium
Gibraltar 1-4 Greece