Petter Northug of Norway dominated a men's 15-kilometre classical race Sunday to gain ground in the overall cross-country World Cup standings, while Justyna Kowalczyk all but sealed the women's season title with another victory.

Northug led from the start to win in 34 minutes, 35.6 seconds. Alexey Poltoranin of Kazakhstan was second, 31.7 seconds behind, while Martin Johnsrud Sundby of Norway was 35.1 back in third.

The victory puts Northug 123 points behind overall leader Dario Cologna of Switzerland with six races to go. Cologna skipped Sunday's race.

Alex Harvey, of St-Ferreol-les-Neiges, Que., was the top Canadian in 41st.

Kowalczyk is virtually assured of winning her fourth overall title after extending her advantage to 581 points over second-place Therese Johaug of Norway.

The Polish skier clocked 25:38.9 in the women's 10K race Sunday to beat Marit Bjoergen of Norway by 23.1 seconds. Heidi Weng of Norway was third, 25.5 back, while Johaug was fourth.

Kowalczyk won three straight overall titles between 2009-11.

Daria Gaiazova of Banff, Alta., was the top Canadian in 33rd.