Manager Jon Dahl Tomasson made seven changes from side that began the toothless display on Saturday, opting for a 3-4-2-1 formation, instead of a 3-5-2.
It took just seven minutes for his changes to be vindicated, when one of the players brought in, Emil Holm, applied a finish from inside the six-yard box.
But Sweden had one of the men who retained their starting place to thank - Alexander Isak beat the offside trap and drew Northern Irish defenders before selflessly squaring to the unmarked Holm.
The visitors grew into the game and had opportunities through Brodie Spencer and Shea Charles, only for the Blagult to deliver a sucker punch just after the 30-minute mark.
Gabriel Gudmundsson played a nice one-two on the left with Ken Sema before getting to the byline and fizzing a low ball across goal.
Goalkeeper Pierce Charles got down low to deal with it, but could only palm the ball straight to Benjamin Nygren, who tapped his first international goal into an empty net.
The third goal arrived just before the hour mark - a free-kick curled into the box was met by Nygren, who saw his strike clatter off the post and back to Ken Sema.
He arrowed the rebound through a crowded penalty, giving the goalkeeper no chance.
The game was done and dusted five minutes later, when Sebastian Nanasi intercepted the ball in the Northern Irish half, diverting it to Isak, who opened up his body and rifled the ball home from 25 yards, scoring his 16th goal for his country.
Tomasson brought on Niclas Eliasson and Anthony Elanga for the final 20 minutes, and they took little time to make their impact, Elanga arrived at the back post to cushion in Eliasson's curling cross for 5-0.
Five nearly became six late on, when Besfort Zeneli struck a 20-yard first-time strike against the crossbar.
Zeneli did play his part in goal number six, but only to deflect Isaac Price's strike past goalkeeper Viktor Johansson as the visitors grabbed a consolation in the last minute to make it 5-1.
Next up for Sweden is another friendly against Hungary in June, before beginning their 2026 FIFA World Cup qualifying campaign against Slovenia in September.