Olympics-Cross-country skiing-Finland's Niskanen takes gold in 50 km mass start

Bolshunov, representing the Olympic Athletes from Russia, took silver 18.7 seconds behind Niskanen, with fellow OAR racer Andrey Larkov beating Norway's Martin Johnsrud Sundby to take bronze.

The Olympic programme usually saves this most gruelling of races for last and because of the huge demands it places on the endurance of athletes it has previously been dogged by allegations of blood doping.

Two of the three Russian athletes who swept the podium in Sochi, winner Alexander Legkov and runner-up Maxim Vylegzhanin, had their medals stripped from them before being reinstated by the Court of Arbitration for Sport (CAS) in 2017.

In a strong field, Niskanen made his breakaway attempt at around the 20km mark, gradually easing away from a group of a dozen skiers though Kazakhstan's Alexey Poltoranin remained hot on his heels.

At the halfway point the pair led with a gap of 11 seconds to the rest of the pack and the Norwegian trio of Sundby, Niklas Dyrhaug and Hans Christer Holund seemed to be biding their time before making their move, but it never came.

Instead, Bolshunov took up the chase after Niskanen, passing Poltoranin at around the 30km mark and blazing after the leading Finn, with the trailing pack now more than a minute behind.

Every time Bolshunov came into view, Niskanen seemed to up the tempo even more to restore his advantage, but with 15km to go Bolshunov started to close in on the Finn and by the time they entered the stadium again the lead had been wiped out.

Bolshunov passed him shortly afterwards and a titanic battle between the two ensued, with Niskanen content for Bolshunov to lead for several kilometres before making a final switch to fresh skis.

Rejuvenated, Niskanen made his break for gold with about one km to go, steaming past Bolshunov and pumping his ski poles for all he was worth.

His Russian rival seemed spent and could not respond, leaving the Finn to coast to a gold medal which will delight his countrymen, starved of success at recent Olympics.

Normally quiet and reserved, the 26-year-old burst into a broad smile, lifting his arms as the crowd rose to their feet to applaud him, led by a raucous band of jubilant, blue-and-white clad Finns.

"I hope it's the first but not the last," a delighted Niskanen said of his gold medal, his second following Finland's team sprint victory in Sochi four years ago.

"For me it's always hard to save energy to the end but today I managed to be first at the finish line, so maybe the coach is not so angry because I didn't go as planned," he said with a smile.

"I could handle the pressure, everything went perfectly today and that's the result," he added.