Ford Fiesta RS WRCs swept the podium places, with Mads Ostberg second and Jari-Matti Latvala third.
Hirvonen defied predictions that he'd struggle as the first car on the road over the final day to take his 13th career victory, and second successive in Sweden, by a scant 6.5s.
“I was really nervous before the last stage but what a fantastic start from the team with the new car,” said Hirvonen
“The car has been quick straight away and after a tough season last year I am really pleased with this.
“But I am not taking this feeling any further.
“We've won here and now we need to move on to the next round in Mexico where it will be a different game.”
Ostberg's performance in Sweden has seen him emerge as a potential rally winner this season.
The Norwegian trailed Hirvonen by just 4.9s heading into the final 4km stage, having led the rally for much of the first two days.
Sebastian Ogier ended the rally as the top Citroen pilot in fourth, and took out the inaugural ‘Power Stage' finale. Shown live on television, the stage carries three championship points for the winner.
The final stage featured the unusual sight of Petter Solberg and co-driver Chris Patterson swapping roles, after Solberg's driver's license was taken away by local authorities for speeding on a road section earlier in the event.
Patterson, having never driven the Citroen DS3 WRC before, clocked the slowest time on the stage, allowing Ogier to take fourth in the rally result.
Loeb's distant sixth place, after being heavily delayed on Friday, was boosted slightly by scoring two bonus points for achieving the second fastest time on the Power Stage.
The WRC heads west to Mexico for round two of the series from 3-6 March.
See below for the results of Rally Sweden
|Khalid Al Qassimi