Cristiano Ronaldo's Portugal began the night in second-place in Group B, needing to take all three points against league leaders Switzerland to seal an automatic spot at the next summer's tournament.
European champion Portugal will get a chance to keep its momentum going after qualifying for next year's World Cup with a 2-0 victory over Switzerland on Tuesday.
The global megastar was pictured in the crowd as an own-goal from Johan Djourou and an Andre Silva strike helped Fernando Santos's side beat Switzerland 2-0.
Portugal coach Fernando Santos is also counting on his captain to lead the way to Russian Federation.
Switzerland, which had led Group B since the first round, will have to go through a playoff to try to make it to the tournament in Russian Federation. Switzerland will now enter Tuesday's draw for the play-offs.
But AC Milan striker Andre Silva forced Yann Sommer into a smart early save from his deflected shot, with the Swiss goalkeeper then forced to make a terrific stop to tip over Bernardo Silva's venomous effort.
That seemed to spring a catalogue of bad decisions by the official and Switzerland felt they should have had a penalty in the 32nd minute when Haris Seferovic was clipped by Eliseu only for the referee to wave play on.
The Swiss were cool and comfortable for the first half hour, stringing together some neat moves in midfield, while Portugal were let down by poor crossing and struggled to get the ball to Ronaldo.
Eliseu clipped a low cross into a risky area at the near post where Joao Mario and Sommer lunged towards the ball. A quick exchange of passes freed Silva on the right and his low cross was turned in by Andre Silva at the second attempt to send the Estadio da Luz into raptures.