Portugal brought a 1-0 lead into their second leg in Solna and after a forgettable opening 45 minutes the game came to life in spectacular fashion with Ronaldo and Zlatan Ibrahimovic taking centre stage.
Ronaldo opened the scoring on 50 minutes before Ibrahimovic then claimed a quick-fire brace to give the home side real hope with Portugal only leading on away goals.
But then Ronaldo took over as he claimed two more wonderful goals in two-minutes to kill off the tie and send Portugal to the World Cup finals next summer.
Sweden had started the match well but struggled to grind out any real chances and it was Portugal who threatened with Ronaldo flashing a couple of efforts wide whilst Andreas Isaksson got down well to another chance from the Real Madrid superstar.
The best chance of the opening half came for Hugo Almeida just before the break as Ronaldo found him at the back post but the Besiktas man headed into the side-netting.
Sweden brought on veteran Anders Svensson at half-time as they looked to push on, knowing they needed a goal and they almost got it on 49 minutes.
Ibrahimovic held of Veloso before sliding the ball into the path of Seb Larsson, who toe-poked an effort at goal which Rui Patricio had to parry away.
Then within 60 seconds - Portugal were ahead as Joao Moutinho played a sublime pass into the path of Ronaldo, who took the ball to the edge of the area before firing left-footed past Isaksson.
Portugal were looking comfortable, but then Ibrahimovic gave Sweden some real hope with two-goals in four-minutes not long after the hour mark.
He levelled the scores on the night as he headed home Kim Kallstrom's corner before then smashing home a free-kick from the edge of the box.
Suddenly Portugal were rocking and Sweden thought they should have had a penalty as Kallstrom went down in the box under Joao Pereira's challenge - but instead the Swedish midfielder was booked by English referee Howard Webb and replays showed the Premier League official was spot on.
Then Ronaldo took charge and lead his side to the World Cup finals with two more pieces of brilliance.
With Sweden pressing and just 13 minutes left, Portugal broke at speed and Almeida played a great ball through to Ronaldo who again fired home with great aplomb.
Then just two minutes later, and the tie was put well and truly beyond Sweden as Ronaldo latched onto another excellent ball from Moutinho and he took it past Isaksson before firing into the roof of the net.
Ronaldo even had time to poke the ball wide for his own fourth, but that was of no consequence as he had already done the hard work as his brilliance saw Portugal to the World Cup finals next summer.