Nilsen, who was called «a hobbit» by one of the judges earlier in the competition, was voted number one by ten of the eleven countries participating in the contest.
He won with U2's song «A Beautiful Day».
The plumber and hobby singer from Bergen on the west coast of Norway was stunned after the victory.
- I needed five minutes in the back room by myself. This was just too much for me, said the happy winner.
American Kelly Clarkson, who has already sold 2.5 million albums, trailed Nilsen to the second spot.