Overall World Cup leader Therese Johaug led her compatriot by 4.5 seconds after stage two and began at a fast pace as she looked to extend the advantage further.

With Johaug having claimed seven consecutive victories in International Ski Federation (FIS) Cross-Country World Cup races before the race, it came as a surprise when Østberg started to close in on the favourite for the overall victory.

After drawing level after 2.5km, the 25-year-old attacked her rival and Johaug proved unable to respond to the acceleration.

Østberg continued to move clear and eventually finished in the fastest time of the day in 12min 57.80sec, with her fellow Norwegian coming in 13.80 seconds behind to fall 9.3 seconds behind in the overall standings.

“Now I deserve the red bib [awarded to the overall leader],” said Østberg.

“It was really hard today, my legs were really tired at the end.

“It was my plan to catch Therese early and do my best, I am looking forward to the rest day.”

An all-Norwegian top three in the current standings in completed by Heidi Weng, who is now 2:03.60 behind the race leader, but holds a 27.2 second advantage over fourth place Charlotte Kalla of Sweden.

Martin Johnsrud Sundby, meanwhile, extended his lead over his fellow Norwegian Petter Northug after finishing the 10km pursuit event in a 21:44.70.

After beginning the day 1:18 clear, the winner of the last two editions of the Tour de Ski, now is 1:25 ahead of the 29-year-old Northug.

While Didrik Tønseth occupied third position at the start of the day to complete a Norwegian top three, he was overtaken by team-mate Finn Hågen Krogh after he produced the fastest time of the pursuit event by completing the distance in 21:20.00.

Krogh remains 1:50 behind the race leader Sundby as the event now heads to Oberstdorf in Germany with the men’s and women’s classic sprint races due to take place on Tuesday (January 5).