"I'm so happy and so thankful and so grateful and I never thought that we could do this," said Lena Meyer-Landrut, who just completed her high school exams.
It's the second time Germany has won the legendary song contest in its 55-year history after Nicole's “A Little Peace” in 1982.
Dark red lips trembling with emotion, the singer told the show's hosts she did not feel strong enough to lift her trophy.
"Thank you! This is so absolutely awesome and I feel like just, this is not real," she said, a German flag in her hands.
In a competition that has come to be dominated by eastern European countries who favour super-glamourised, American-style performers, Lena came across as a refreshingly unpretentious teenager plucked from the streets of Hannover.
Untrained, unprofessional, and conspicuously adolescent, Lena, who turned 19 last weekend, has been phenomenon in Germany since winning “Our Star for Oslo” in March. Since then, Lena debuted with three singles in the top five of the music charts after being taking under the wing of German TV personality Stefan Raab.
She had been considered one of the favourites to win Eurovision and Germany will now host the show next year.
Organisers said more than 120 million viewers across 39 European countries, but also as far afield as Burma, Australia and New Zealand, tuned in to the contest, one of the world's most watched events.
The show took place without any major incidents, but one of the 16,000 fans who had packed Oslo's Telenor Arena to watch the contest live managed to slip through security and onto the stage during Spain's performance.
Some in Spain identified the intruder as Jaume Marquet Cot, better known as "Jimmy Jump", a real estate agent from the separatist-minded region of Catalonia who is known for pitch invasions of several major sporting events.
They accused him of trying to ruin Daniel Diges' chances of winning Eurovision with "Algo Pequenito."
A total of 25 countries were competing in the final for the winner's prize, selected by specialist juries and by viewers voting by phone or text message in the 39 countries that took part in the contest.
Turkey, Romania, Denmark and Azerbaijan respectively came in to take the other top spots behind Germany.