Carlsson, looking to become the third consecutive Swede to win this event since it moved to Bro Hof Slott after Richard S Johnson and Alex Noren’s victories in 2010 and 2011, carded eight birdies and dropped his only shot of the day at the 18th.
The 31 year old, whose runner-up finish in Madeira last month matched his best European Tour performance, had five birdies in six holes from the seventh as he made a dazzling burst around the turn.
“Now I’m focusing on having fun out there on the course,” said Carlsson. 
“To be on top of the leaderboard at a European Tour event - I can’t be anything else other than very satisfied, especially on a tough course like this one here at Bro Hof.
“Now I just want to go home and get some rest to be prepared for tomorrow and the rest of the tournament.”
Richard Bland, another player seeking his maiden European Tour title, set the morning pace with his five under 67.
The Englishman, who only retained his European Tour playing privileges for this season via a trip to Qualifying School, recovered from a bogey at his first hole, the tenth, and a double bogey seven at the 13th with eight birdies.
Two of those came in the holes between his blemishes, with four birdies in a row from the 16th and further gains at the third and sixth.
“To shoot five under round this course at anytime is good,” said Bland, playing in his 275th European Tour event.
“I had a bit of an up and down start but I kicked it into gear around the turn, which made the day really. I played the front nine, which was my back nine, pretty solid, so the game’s in pretty good shape.”
He was joined in the afternoon by compatriot Matthew Baldwin, Spain’s Ignacio Garrido and another home favourite, Peter Hanson – who holed from ten feet at the 14th and chipped to three feet at the next for two of his six birdies.
“It was good, I was a bit nervous teeing off,” said Ryder Cup star Hanson. “I haven’t been too happy with my game lately so it’s nice to get off to a good start.”
World Number Three Lee Westwood completed a four under 68 despite three-putting twice, while his Ryder Cup teammate Sergio Garcia mixed six birdies and three bogeys in his 69, the highlight a 25 footer at the last.
“I played quite nicely,” said Westwood. “You have to hit the fairways, but if you do then you’ve got a good chance. The rough is fairly penal.
“It’s long so you have to hit driver a lot of the time - it’s just a good test.”
There were some brilliant shots as great rounds, Rafael Cabrera-Bello coming within an inch of an ace at the par three seventh during his round of 71.
Leading scores on Wednesday after the first round of the Nordea Masters (par-72):
65 – Magnus A Carlsson (SWE)
67 – Richard Bland (ENG), Peter Hanson (SWE), Matthew Baldwin (ENG), Ignacio Garrido (SPN),
68 – Michael Jonzon (SWE), Carlos Del Moral (SPN), Emiliano Grillo (ARG), Robin Wingradh (SWE), Lee Westwood (ENG), Daniel Denison (ENG), Alejandro Canizares (SPN), Andy Sullivan (ENG)