They spent months together in Gleason's gym. Afterwards, the actress left a note: "Maureen, you're awesome, you're going all the way and I'll be watching."

Shea, who is fighting in Reno, Nevada this weekend, is ranked in the top 10 of the super featherweight division by all the boxing sanctioning organisations, and as world No 1 by the WBA. She is aiming for a tilt at the world title next year.

Her story is as riveting as any Hollywood script. She grew up in the Bronx, the daughter of an NYPD detective whose family come from Co Kerry.

"As a teenager, I was rebellious. I was kicked out of high school. My dad was very strict. If I came home after curfew, he locked me out. I'd to sit in the backyard for the night. He practised tough love and I marched to my own drum . . . I still do."

Shea became involved with a man six years older. "He was an angel in the beginning, then he changed. He became emotionally and physically abusive. He said I was fat. I took diet pills. I thought if I was thin, he'd treat me better. I became anorexic."

Shea caught her boyfriend cheating on her. She broke the other girl's nose: "I knew then I needed to channel my anger into something positive." Aged 19, she walked into a health and fitness gym.

"They had boxing at the back . . .that's how it began. I fell out of love with my boyfriend and in love with boxing. It helped me regain my pride and self-esteem. Boxing loved me unconditionally. I always got back what I gave. Boxing became my father, my mother, my husband, my everything."

Years earlier, as a child, she'd been dazzled by a fight: "I'd watched Mike Tyson on TV. He bit off Evander Holyfield's ear. I was fascinated. I wondered what kind of sport someone would go that far for."

At first sight, you wouldn't put Shea (26) anywhere near a boxing ring. She's 5ft 4in with long auburn hair, green eyes, and a beautiful open face. "When I was starting out, I was constantly told I was 'too pretty to fight'. But women can carry themselves with class and elegance and still box. I'm a real girlie girl. I get manicures, pedicures and facials."

Oddly for a boxer, Shea is a vegan.

She has 10 wins . . . five by knockout . . .under her belt. In her professional debut, she knocked out her opponent just 38 seconds after the first bell. "It felt incredibly good, " she says. One observer told her, "If it wasn't for the ponytail and figure, I'd have thought you were a guy." It was "the best compliment I've ever received", Shea says.

She hates when it's called 'women's boxing' and not just 'boxing'. "In the ring, women sweat and bleed just like men." When she was starting out, women fighters received little respect from male boxers and trainers: "People would come into Gleason's and laugh when they saw me. I'd say, 'Come to one of my fights.' I'd let my hands do the talking, not my mouth.

"Female fighters are now taken more seriously. Million Dollar Baby has also helped bring more women into the gym. When I began boxing, my parents told me I was crazy. The other day my father said, 'It's to your credit Maureen, you persevered and I'm proud of you.' That meant the world to me."

Shea has a boisterous Irish following in New York: "They're fantastic. I've never even been to Ireland. I'd love to fight there." She's finishing an English degree at Iona College. If she's fighting outside New York, she takes her books to read on the journey. "I love Greek mythology . . . my cat is called Pandora."

She has sacrificed much for boxing: "It's become my life. Meeting men can be difficult. They don't approach me because they're intimidated. But I know when the time is right, the right man will come along.

And he'll get me . . . for who I am."