Tove Alexandersson of Sweden also performed superbly to successfully defend the corresponding women's title on the Rouge course. 

Lundanes set a furious pace from the outset of the 17.1 kilometres men's race by almost sprinting down the run-out route.

He did not produce a perfect running performance, coming close to missing several controls, but ultimately persevered to triumph in 1 hour 45min 25sec. 

It followed his earlier victories in 2010, 2012 and 2016.

“I am really really happy I managed to win two years in a row, and also get my fourth long distance gold," the winner said.

Russia's Leonid Novikov finished almost two minutes behind when clocking 1:47.15 for second.

Sweden's William Lind took bronze a further 23sec behind. 

Alexandersson ensured more success for Sweden by repeating her 2016 success over the 11.4km women's course.

She clocked 1:19:10 to finish 92sec clear of Denmark's sprint world champion Maja Alm.

It came after Alexandersson had missed the sprint final as she recovered from a heavy cold.

Russia's Natalia Gemperle clocked 1:24:46 for a distant bronze today.

A rest day will take place tomorrow before competition resumes with middle distance finals on Thursday (July 6).