The Norwegian claimed a historic victory in front of a home crowd in what was the first time the discipline has been contested at the World Cup.

Haga's finishing time of 2hr 13min 36.1sec was enough to see her narrowly triumph in a thrilling finish as compatriot Astrid Øyre Slind followed her across the line just 0.3 later.

The United States' Olympic and world champion Jessie Diggins then made up the podium 0.5 off the pace.

Haga said the win was almost as special as when she won two gold medals at Pyeongchang 2018.

The 32-year-old was in 15th position after 20km but made her way to the leading back where she stayed at the rear before surging to the fore for gold.

"I think it's the second-best day of my career after the Olympics in 2018, winning here on home soil," she said.

"I tried to save as much energy as I could because I understood that the last uphill, to Frognerseteren, was hard and then it was about to save energy for the last two kilometres."

"I've done the sprint of the last 100 metres here so many times in training, so I knew that I was just doing all I could to win today."

The result was the first individual World Cup win for the Olympic 10km freestyle and 4 x 5km relay champion.

Despite being so close to victory, Diggins was still happy with her podium finish and feels the race marked a milestone in the sport.

"That was so cool, to finally get to do 50km - I've been wanting to do this my whole career and I don't want to go back, now that we finally have true equality between the genders in our sport," she said.

She overtook Finland's Kerttu Niskanen in the overall World Cup standings and now sits second on 1,548 points but trails leader Tiril Udnes Weng of Norway on 1,635.