Petter Northug maintained his lead at the top of the Tour de Ski standings with a stage five win in the 25 kilometre freestyle pursuit event at Torblach, Italy.
In the women's event, runaway leader Marit Bjørgen continued her 100 per cent record with another dominant performance to extend her advantage to 2:03.8 over compatriot Heidi Weng on the overall leaderboard.
Northug started with just a 1.5 second advantage ahead of reigning Tour champion Martin Johnsrud Sundby, but by the end of the fifth stage that lead was seven seconds.
Sweden's Calle Halfvarsson finished second in front of Johnsrud Sundby, while another strong performance from Evgeniy Belov kept him in contention as he trails Northug by 17.4 seconds.
"Martin was very strong, when he increased the speed we could gain many seconds and also Belov did a lot of work," Northug said.
"I was tired in the third and fourth lap, I tried to save some energy for the last lap.
"It is a close Tour de Ski and we will see what happens in the mass start in Val di Fiemme."
Great Britain's Andrew Musgrave produced the fastest display of the day ahead of France's Maurice Manificat, which moves him into 11th place.
Meanwhile in the women's event, Bjørgen proved too strong once again as she finished 1:58.8 quicker than Weng, and Therese Johaug came in third.
"No victory is easy but I felt amazingly strong and I could focus only on my performance," Bjørgen said.
"I am happy I could increase the gap little bit and I am looking forward to the next competitions.
"It looks good for me but there are still two competitions until the end."
Two stages remain of the event, and tomorrow will give the skiers a welcome rest day from the recent gruelling schedule.
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