Portugal head coach Fernando Santos thanked his players for securing the "gift" of World Cup qualification.
The European champions headed into their final qualifier in Lisbon three points shy of opponents Switzerland, who overcame them in the Group B opener in Basle last September.
Both teams won every qualifier between that match and Tuesday's decisive showdown, where a Johan Djourou own goal and Andre Silva's 57th-minute strike ensured Portugal progressed to Russia 2018 on goal difference.
"I always thought it was possible," Santos told reporters afterwards. "I had confidence in my players and luckily they gave me this gift.
"When you have quality and organisation you are always closer to winning. This team came back to play very well, with good ball control.
"Not all of the 90 minutes were perfect but fortunately we won and we are in Russia."
Portugal famously reached the semi-finals of their triumphant Euro 2016 run without winning a game inside 90 minutes and Santos hailed their dressing room spirit after overcoming adversity once more.
"There is a perfect symbiosis between coach and players," he said.
"I always believe in my players. It is not easy to have 25 players with this mindset and it creates a fantastic environment.
"I believe in our work, in the work of the technical team and in the work of the federation. It is this collaboration that gives us this result."
Bernardo Silva missed Euro 2016 through injury but Manchester City's former Monaco playmaker was to the fore to help seal victory with a superb display.
Grande noite! Estamos no Mundial! Obrigado a todos os portugueses que estiveram presentes no Estádio da Luz. Ambiente fantástico pic.twitter.com/CqpSOzskj2-- Bernardo Silva (@BernardoCSilva) October 10, 2017
"Fernando Santos always gives a lot of confidence to the players and is on our side," he told reporters.
"As we did in the European Championship, we always try to win. So we will try to win the World Cup."