Former supermarket check-out worker Michelle Dewberry, 26, has won the second series of BBC Two's The Apprentice.
She beat her "gutted" rival Ruth Badger to earn a £100,000-a-year job working for tycoon Sir Alan Sugar.
Sir Alan told her "you're hired", before praising a lifetime of hard work and branding her "a great achiever".
Ms Dewberry, from Hull, went into business after the death of her sister, and ran a telecoms company aged 24.
She said it was "unbelievable" to have been chosen.
"It wasn't until right at the very end when he said I'd won that I believed it.
"It shows you don't need to be loud and cocky and 'bolshie' - just work as hard as you can, and hopefully you will get on in life."
Fellow finalist Ms Badger, a 27-year-old sales manager from Wolverhampton, found it hard to hide her disappointment at losing.
The finalists spent some months working for Sir Alan before the final showdown
"I'm genuinely, genuinely happy for Michelle but I'm absolutely gutted that I'm not working for Sir Alan," she admitted.
"I've never in my career or my life fought for something so much. There's nobody in this country that inspires me more than Sir Alan.
"Even though I've come second, I absolutely worship the man."
Sir Alan said he was in "a terrible dilemma" about which of the two to employ.
"Last year was easier. There was no contest," he said, referring to Tim Campbell, the transport manager who won the first series of the programme and has spent the past year working for the entrepreneur.
Ms Dewberry and Ms Badger were "both very employable people" with "tremendous skills".
However, he said the role he had in mind for the winner - disposing of the unwanted computer equipment of other businesses - would be more suited to Ms Dewberry.
"I found her very focused, very determined, very organised, and this particular job I have in mind requires all of those skills.
The 2005 winner, Tim Campbell, has been working for Sir Alan for the past year
"She's young and willing to learn. I think I've got the right girl."
The final episode of the second series saw the pair competing to stage a show-stopping party on Tower Bridge in London.
Ms Dewberry chose a James Bond theme but Ms Badger failed to impress with her murder mystery evening.
In the audience to watch the programme were all the other contestants from this series, and the families of the finalists.
Ms Dewberry's mother Glynis said she was "so proud" of her daughter, who had always been "very determined" and "always knew she wanted to go far in life".
Although she failed to win, Ms Badger may still have a future with Amstrad as Sir Alan said they would be meeting soon to discuss job opportunities.