OSLO — Norway's Martin Johnsrud Sundby won the cross-country skiing World Cup title on Saturday with victory in a 50-kilometre classical race.

Sundby has been a controversial figure this season after serving a two-month doping ban last year for exceeding the permitted dose of asthma medication.

Saturday's win gives Sundby an insurmountable lead in the standings for his third career World Cup title. He was stripped of another title from the 2014-15 season as part of the doping sanction.

Canadian Alex Harvey, who won the world championship in the 50-km race last week in Finland, finished sixth.

The 28-year-old Harvey completed the marathon race in a time of two hours, four minutes 15.1 seconds after the sprint finish.

"Being that close to the podium is heart breaking, but none of the guys ahead of me did the sprint this week so I think I got beat by someone who was a little more fresh than me," said Harvey who was looking to become the first athlete ever to win the 50 in back-to-back weekends at the World Championships and the Holmenkollen.

"I had a really bad sprint today. The conditions were really warm and wet. I was cramping all over the place so it wasn't a good finish. But I'm in good shape and have to be happy with the sixth today."

Sundby and Finland's Iivo Niskanen fought out front in Saturday's race before Sundby opened a lead over the Finn with three kilometres to go.

Sundby won by 9.9 seconds from Niskanen. More than a minute behind, Russian Alexander Bessmertnykh was third in a photo finish with Norwegians Sjur Roethe and Niklas Dyrhaug.