The Great British Bake Off is BBC Two's most-watched programme in a decade, after an average 8.4 million viewers saw Frances Quinn win series four.
Clothes designer Quinn, 31, said she was "in complete and utter shock" after beating psychologist Kimberley Wilson and former model Ruby Tandoh.
She impressed judges Mary Berry and Paul Hollywood with her wedding cake, inspired by A Midsummer Night's Dream.
At its peak, some 9.1 million people tuned in to Tuesday night's finale.
The episode - which also saw the amateur bakers making pretzels and picnic pie - secured double the audience tuning into the Uefa Champions League football match which was broadcast on ITV at the same time.
The hit show, which moves to BBC One next series, beat the record held by a 2007 episode of Top Gear, by more than 400,000 viewers.
Bake Off presenters Mel Giedroyc and Sue Perkins had billed Quinn, who lives in Market Harborough, Leicestershire, as "the most creative baker to ever set foot in the tent".
She said she was looking forward to celebrating with family and friends, after having to keep her win under wraps since recording the final episode during the summer.
"I've been back at work and trying to keep a poker face," said Quinn.
"I remember watching the Wimbledon final the following week and getting so emotional... and thinking at least Andy Murray doesn't have to hide his trophy under his bed for the next three months."
Quinn said she was shocked to hear her name: "I don't think I could speak for a little while. It was so close, such a close final," she said.
However she insisted there was no antagonism between the all-female finalists.
"We all get on. People want to feel there was more competition than was the case," she said.
"The emotions you go through in that tent - you never want to see anyone get that criticism. Outside the tent we're just supportive of each other."
Hollywood called Quinn "a deserving winner", who beat the others "hands down" in the showstopper round.
"She not only gave us the style, she gave us the substance too and that cake actually, each layer, superb," he said.
Fellow judge Berry added: "She has attention to detail, she's got excellent flavours, her baking improved as each week went by. We're very proud of her."
Quinn said she was not thinking of leaving her design job, although she has already been approached by agents and hopes to produce a book.
"Work has been so, so supportive. I'm not going to say yay or nay to anything at the moment, I've got a mortgage to pay," she said.
"The baking market is completely saturated so I don't want to do a book that's anything like one that's already out there. I'd like to create a book that's got all my rough sketches and ideas."
"I don't know what the future is going to hold but it does excite me. What I'd love to do is combine both passions, baking and design."
'Vitriol and misogyny'
Meanwhile runner-up Tandoh, 21, has hit back at the "nastiness" the show and its contestants were subjected to, in a piece written for The Guardian.
"Despite the saccharin sweetness of the Bake Off, an extraordinary amount of bitterness and bile has spewed forth every week from angry commentators, both on social media and in the press," she wrote.
"Many took to Twitter decrying the demise of the show, voicing their hatred for certain bakers, and asserting (week after week!) that they would 'never watch it again' if X or Y got through that episode."
The amateur baker - who recently received a first class honours degree in philosophy - said the criticism ranged from "gently cynical" to "downright obnoxious", and as the series went on she noticed "an increasing amount of personal vitriol and misogyny".
Tandoh, who chef Raymond Blanc suggested was too thin to enjoy food, said she was "tired" of defending herself against the "boring, inevitable accusations of flirting with Paul Hollywood, of emotionally manipulating the judges and of somehow surfing into the final on a tidal wave of tears".
She added: "So much of the criticism levelled at the bakers is gender-specific. My self-doubt has been simultaneously labelled pathetic, fake, attention-seeking and manipulative."