More than 12 million viewers watched Michelle McManus win ITV's Pop Idol - two million fewer than the first final two years ago won by Will Young.
Michelle: "Everything scares me"
The 23-year-old Glaswegian won the TV talent show, beating rival Mark Rhodes, after more than 10 million phone and online votes were cast by the public.
ITV said it was delighted with the ratings for the series as a whole - up on average from the show in 2001.
McManus said it had only just sunk in that she was the new latest Pop Idol.
"I don't know what lies in front of me - it's probably 10 times crazier than what I've been through," she said.
Michelle had been the bookies' favourite to beat 21-year-old Mark, from Walsall in the West Midlands and triumphed despite questions over her weight and image.
"I cannot believe this single is about to be played on the
radio. I think I will just pass out," she told DJ Neil Fox, who was one of the judges, on his Capital Radio show.
A spokeswoman for the network said: "Obviously we are delighted that not only has this series done so well, it has outperformed the success of the first
series of shows."
At a press conference following her win, Michelle she told
reporters: "You're probably better asking me what doesn't scare me.
"Absolutely everything scares me. I was nobody six months ago. I haven't come
"It's not as if I've been trying to do this for years and years
The newly-crowed Pop Idol will release a single, All This Time, in the New Year.
The 15-stone singer said she wanted to release songs that were "edgy pop".
"I'm never going to be Atomic Kitten - in more ways than one," she said.
It is uncertain if the singer will find lasting success - winners of TV reality pop programmes have enjoyed mixed fortunes.
While the first Pop Idol Will Young continues to find chart hits, bands such as Hear'Say, One True Voice and singer David Sneddon, who won similar talent shows, have disappeared into obscurity.