Michelle went from Walford Square to Hollywood's Bionic Woman

For most actors, abandoning a top-rated soap opera is career suicide. With viewers unable to accept them as anything but their popular character, their options are often reduced to pantomime and reality TV.

But former EastEnders star Michelle Ryan has just achieved the impossible, managing to ditch the image of dowdy Albert Square market trader Zoe Slater to become a robotically enhanced action heroine in one of the biggest new shows on American TV.

Strong woman: Michelle is now a prime time US star

Against all expectations, and to the certain envy of her former co-stars, the 23-year-old Londoner landed the lead role in a £25million remake of Seventies series The Bionic Woman for the NBC network.

Its opening episode last week pulled in 14million viewers, the best ratings the channel has seen for a new Wednesday-night show since The West Wing in 1999.

Superstar: Michelle Ryan has blossomed into a 23-year-old woman

Michelle beat scores of other actresses, including Friends star Jennifer Aniston, to the role of Jaime Sommers, a barmaid who, after nearly dying in a car accident, is given cybernetic body parts that leave her with superhuman strength, hearing, vision and speed.

Rights to the series were quickly snapped up by ITV2, which plans to show the series in Britain in the New Year.

Eastenders: Jessie Wallace (left) and Michelle Ryan in their Walford days

It is a phenomenal achievement for an actress who became synonymous with her troubled character over her five-year career in the soap she joined at the age of just 15.

But Michelle is keen to downplay her new success, saying simply: "It does feel like a fresh start. I'm so well-known in England for playing Zoe, who was quite a soft, even slightly weak, character. So I love the fact that I'll be known as a very strong, feisty character, and I think it's a nice progression for me."

Wet and wild: Michelle as Bionic Woman

In reality, the role is more than a "nice progression".

It has launched her into a different league, taking her from Albert Square to the vast Bionic Woman set in Vancouver, where two ten-storey-high cranes tower over the site, supporting the zip lines and harness needed for the complex stunt scenes. Michelle does all her own stunts and is often on set for more than 12 hours a day.

US Hit: Bionic Woman is already making waves

There are complicated fight scenes and terrifying jumps in every episode.

Creator David Eick says: "Michelle is so committed that every day from morning to night she was in one class or another. Michelle was in Dojo (a Japanese-style martial arts training hall} taking Krav Maga, which is like dirty street fighting."

So just how has Michelle succeeded where so many others – such as fellow ex-EastEnders Martine McCutcheon and Tamzin Outhwaite - failed?

Sexy star: Michelle landed the lead role in the £25 million remake

Certainly her looks have helped.

A healthy size 12, Michelle has the height and athleticism the part demands, yet combines it with beauty and glamour. But even this does not explain how she managed to beat off such fierce competition, given she was unknown in America.

The answer may lie in the quiet but steely determination she has shown from a young age.

The eldest daughter of Craig, a former fireman, and Tina, a beauty adviser, Michelle joined a theatre and dance group near her Enfield home when she was just ten. From there, she took part in a drama workshop set up by EastEnders producers who wanted to introduce a new family, the Slaters.

Action-packed: Michelle Ryan in new series

Michelle says: "My parents had no idea of what it would entail. You're still a child but you're put in this adult environment and it's a real shock. I had a very idyllic view of life when I came into EastEnders, and you soon realise that you have to stand up for yourself.

"You want to be everyone's friend, and you want everyone to get on, but things just don't work like that sometimes."

After two-and-a-half years on the show, Michelle was forced to take four months off, suffering from exhaustion. And she finally left three years ago because "it just got really boring".

She said: "It was too easy. I got to the point where I needed a new challenge. I was 21 and desperate to go out and meet some new people."

She went for the role of Bond girl Vesper Lynd in Casino Royale but lost out to Eva Green, co-starred in the low-budget British film I Want Candy, then appeared in the acclaimed fringe play Who's The Daddy? about David Blunkett's affair.

Muscles: Michelle Ryan has buffed up for her new role

Co-author Toby Young said: "She's got bags of sex appeal. She has a very attractive, wholesome quality that you didn't see in EastEnders but is perfect for The Bionic Woman."

While she was still on EastEnders, Michelle started working with a voice coach to perfect her American accent, and when she left she signed with one of LA's most powerful talent agencies, The William Morris Agency, who began searching for a suitable role in America. They found it with The Bionic Woman, the role Lindsay Wagner made famous in the Seventies.

Michelle says: "I was just called in to do an audition, so I put myself on tape and that was sent to NBC. They liked what they saw and they brought me out to do a screen test, and then within a week I found out I had the job. I think I got lucky."

Sultry: The ex-Eastenders star has come a long way from Walford Square

In reality, she had been focusing on this goal for years.

Toby Young says: "Her success doesn't surprise me. She's extremely professional and hard-working. It wouldn't surprise me if she starts dating a Hollywood movie star."

Certainly, her former fiance, 28-year-old semi-professional footballer Tommy Williams, has fallen by the wayside.

Zoe ended the three-and-a-half-year relationship just as she got the part of Bionic Woman, yet Tommy's mother, Gillian, still says: "She's a lovely girl and we wish her all the best. She deserves it."

David Eick, also a producer on the show, says: "When Michelle came to this role she had a lot of things she wanted to perfect. She looked at it not just as a great opportunity career-wise but an opportunity to reshape who she was so she could fit into this role as perfectly as possible."

If the actress has her way it will be the Bionic Woman, Jaime Sommers, not Zoe Slater, that she is remembered for.

She says: "I so got Jaime because she's going to take charge and she's going to be in control and she's going to own her life."

Just like Michelle Ryan.