Perrelli, who as Charlotte Nilsson won the contest for Sweden in 1999, beat off competition from Sanna Nielsen and BWO thanks to the votes of professional juries established by contest organizers SVT. The telephone votes of television viewers put Nielsen in first place, but these were outweighed in the final reckoning by the jury votes.
"It is so different now. Every stage is so closely watched. Also I was an unknown in Sweden then," Perelli said to SVT after her success.
Although she appeared nervous as the votes were reported back to Stockholm's Globen arena from around the country, Perrelli had been hotly tipped to win with her upbeat, glamorous disco number. Perelli confirmed to SVT how nervous she was as the votes were coming in.
"So many of the favourites have been knocked out this year. I took absolutely nothing for granted."
The winning song was written by Fredrik Kempe and Bobby Ljunggren. Ljunggren is a Melodifestivalen veteran, who also wrote BWO's entry Lay Your Love on Me and Sanna Nielsen's Empty Room. In the past he has written hits including Alcazar's Not a Sinner Not a Saint.
Perrelli now has just over two months to prepare for the Eurovision Song Contest, which will be held on 24th May in Serbian capital Belgrade. A rule change means that she - along with representatives of all countries apart from hosts Serbia and the four largest participating countries - will need to do well in semi-finals on 22nd May in order to qualify for a place in the grand final.