The 26-year-old was an impressive 42 seconds ahead of the second placed Marit Bjørgen, also of Norway.
Just 1.4 kilometres into the race, Therese Johaug was over 10 seconds ahead and it began an easy win for the Norwegian.
Therese Johaug. Photo: Terje Bendiksby / NTB scanpix
At first, Johaug was hesitant to confirm the romance rumours connected to her and Hoff, but she did tell the media: "Yes, we are partners, but I don't want to comment more than that.”