Author and actor Jonas Gardell was moved enough to tweet, "Loreen, I am no longer homosexual!!!"
Loreen, 28, real name Lorine Zineb Noka Talhaoui, the daughter of Berber immigrants from Morocco, is the fifth Swedish winner of the contest since Abba
took the title 38 years ago.
Sweden's media said Loreen left the competition trailing in her wake.
"Loreen created euphoria in Europe and swept away the competition," said the online edition of the daily Expressen. Svenska Dagbladet said she "massacred the rest of the competitors."
Prior to Loreen's performance, Swedish media reported she had problems with her throat, casting doubt on whether she would be able to take part in the glitzy contest in Baku, Azerbaijan. As she swept on stage, Sweden sighed with relief.
"My God what a relief... my knees were knocking," blogged Aftonbladet journalist Markus Larsson as Loreen performed her winning number.
The singer's own delight was captured by public television station SVT when she admitted she was not usually a party girl but said "Waoooh... maybe I'll make an exception tonight."
However despite the praise from large swathes of a grateful Eurovision-crazy country, there were some high-profile dissenting voices.
Sweden Democrat party secretary Björn Söder used his Facebook page to question whether Sweden did in fact win, citing the fact that Loreen's song was sung in English.
Söder was subsequently criticised and he has since deleted the comment thread, claiming that he had been threatened.