Cristiano Ronaldo scored with a diving header eight minutes from the end to give Portugal a 1-0 win over Sweden on Friday in the first leg of their World Cup playoff.
Ronaldo transferred his prolific scoring touch from Real Madrid to the international stage, diving to head home the lone goal in the 82nd minute. The second leg is Tuesday in Stockholm.
France faces the prospect of missing a major tournament for the first time since 1994 after Roman Zozulya and Andriy Yarmolenko scored second-half goals for Ukraine.
Kostas Mitroglou scored twice to help Greece beat visiting Romania 3-1.
Iceland held on with 10 men to draw 0-0 with Croatia, keeping alive its chances of becoming the least populous nation to reach a World Cup.
Italy drew 1-1 with Germany and an experimental England side slumped to a 2-0 home loss to Chile in headline friendly matches.
One of the world's top forwards will be absent in Brazil next summer - and it looks more likely to be Ibrahimovic, not Ronaldo.
Ronaldo dived to glance in a left-wing cross for his 44th goal in 108 international appearances, and almost added another when he headed against the crossbar.
Ibrahimovic was largely anonymous in Lisbon and, at the age of 32, could be set to miss out on what would likely be his final World Cup campaign.
Another star of the world game, Bayern Munich winger Franck Ribery, also might be absent in Brazil after France tumbled to defeat in Kiev on a night that proved to be one to forget for Laurent Koscielny. The Arsenal defender conceded the penalty that Yarmolenko converted for 2-0 in the 83rd minute, and was then sent off in stoppage time.
Iceland, with a population of around 320,000, is seeking a place in a major tournament for the first time but the biggest soccer match in the Nordic country's history turned sour when Olafur Skulason was sent off for a professional foul in the 51st.
However, goalkeeper Hannes Halldorsson and his packed defense stood firm to repel wave after wave of Croatia attacks in the second half. The 10,000 Iceland fans in the Laugardalsvollur national stadium greeted the final whistle as if their team had won.
Italy maintained its proud record of not having lost to Germany since 1995 - but needed a 28th-minute equalizer by Ignazio Abate to preserve that run.
Germany took the lead in the eighth minute through Mats Hummels and twice hit the goal frame in Milan.
In another match between two World Cup qualifiers, Chile ended England's 10-game unbeaten run thanks to Alexis Sanchez's double at Wembley Stadium.
The Barcelona forward scored in the seventh minute and again in second-half injury time to deliver a reality check for England, which gave three players debuts.
