Alexandersson won the middle distance in Finnish Kuopio with a 47-second margin to second-placed Aebersold.
But the consistent Swiss, who had not been worse than second all season, could celebrate the overall victory.
Her season is really impressive. I'm happy for her sake, she really deserves it, says Tove Alexandersson in the victory interview on SVT's broadcast.
Tove Alexandersson started the middle distance with a mistake and was 30 seconds behind for a while – but the super Swede came back strong.
It was good, but a bit shaky at the start, I made a few small mistakes. It took a while before I got into it, says Alexandersson, who took her fourth World Championship victory of the season.
More Swedish women stayed high up when Hanna Lundberg finished fourth, 1.01 behind Alexandersson, and Sanna Fast finished fifth.
