The 24-year-old, who won an Olympic gold medal at Sochi 2014 in the team sprint, recorded the quickest time of 35min 27.6sec with the race utilising a staggered start format.

Niskanen had only ever won one World Cup race before, and that also came on home snow in Ruka two seasons ago.

The Finn came home in front of two Norwegians in the second and final race of the opening leg of the World Cup season.

Emil Iversen was timed at 35:37.8 for silver as defending overall World Cup champion Martin Johnsrud Sundby took bronze in 35:38.8.

Sundby served a two-month drugs ban in the summer after his asthma medication caused him to fail two tests, but has made a quick return to the podium.

He was stripped of the overall World Cup and Tour de Ski titles he claimed in the 2014-15 season with the failure blamed on incorrect advice from the team doctor.

In a tight day of racing, just 33 seconds separated the top 10 athletes.

After the first two races of the season, Sweden's Calle Halfvarsson sits on top of the overall standings with 116 points.

Niskanen and yesterday's sprint winner Pål Golberg are in joint second place, both on the 100 points they earned for their victories.

In the women's race today, taking place over 10km, Norway's Marit Bjørgen returned to the sport in sensational style with victory.

The six-time Olympic champion missed the entirety of last season due to the birth of her first child, but has returned this term in search of a fifth overall World Cup title.

The 36-year-old, who has won 14 World Championship gold medals, clocked a winning time of 26:55.2.

Finland's Krista Parmakoski was nearly five seconds behind in silver medal position, stopping the watches at 26:59.8.

Norway's Heidi Weng took the bronze medal in 27:07.9.

"I was leading all the way today," said Bjørgen. 

"I had very good laps. 

"I got very good help from Victoria Carl on the flat sections. 

"She was very strong there.

"It is a great feeling to be back and win again. 

"I know I can win when I have a good day. 

"I train with some of the best skiers in the world so I knew how my shape was."

Sweden's Stina Nilsson, who won the sprint race yesterday, tops the early overall standings on 136 points. 

Bjørgen is second on 126 with Parmakoski third on 125.

Lillehammer in Norway will host the next leg of the World Cup from December 2.