Thousand Dollar Baby: By day Jamie O'Hare studies for a master's in social work. Her night job is anything but.

O'Hare found Finney's gym almost four years ago. At that time, she was strictly kickboxing, her latest obsession on a physical-fitness odyssey that took root after a frightening episode in college.

While a senior at Missouri State University in Springfield, O'Hare was sunbathing with friends one day at the pool when an older man she didn't know began squirting her with a water gun and taunting her with sexual innuendo. Before long, she says, the man "started stopping by my house, bringing me flowers, showing up outside my classes. He knew my whole schedule."

Sometimes at night, she says, the man would cross the alleyway from his halfway house and tap on her apartment door. The stalking escalated to the point where even after O'Hare obtained a restraining order, the man would "stand on the edge of my apartment complex and shoot me threatening looks as if he wanted to kill me."

Angry, O'Hare enrolled in self-defense classes at a Springfield martial-arts studio. She became hooked, to the point where she moved on to kickboxing and within months began teaching other women. It was both an addiction and therapy. As she puts it: "I swear it was better for me than the students."

The incident is not well-known among many of O'Hare's contemporaries. "I had no idea about the stalking until recently," says Cyndi McGee, a sexual-assault victims' advocate and O'Hare's mentor in the city prosecutor's office. "I think it's tremendous that she found the strength to grow from that experience. She definitely doesn't carry that veil or shadow of victimization with her."

O'Hare returned to St. Louis in summer 2004 and joined Jesse Finney's gym in short order, but it took some time before the trainer finally noticed her. "One of my guys pointed her out," Finney recalls. "He said, 'We've got a good one on our hands.' She was aggressive, and pretty tough; she didn't shy away when she got hit. Plus, we like people that are not only hard-working but groomed and clean-cut, the ones that are good people in and out of the ring."

Although women have been stepping between the ropes as far back as the 1700s, the sport has never been exalted for its parity. The 1904 St. Louis Olympics featured the only Olympic female boxing exhibition ever, and boxing is still the only summer Olympic contest (besides baseball) in which women don't get to compete. It wasn't until 1995 that the first Golden Gloves women's bout took place (in New York). Four years later Muhammad Ali's 21-year-old daughter Laila "She-Bee Stingin" Ali staged her pro debut at an upstate New York casino. Ali is now credited by sports historians as having done the most to elevate the profile of women boxers. (Today Ali co-hosts NBC's American Gladiators.)

Finney put O'Hare on an amateur card at a Shriners fundraiser in Springfield, Illinois, for her first competitive bout, in kickboxing. "It was a little smoker show, with no more than 150 people," she says. "The only two females in the whole place were me and my opponent, and I actually had an old man come up to me and ask me if I'd like to have sex with him!

"But it was still a blast. Winning is an awesome feeling, you know, and having the crowd there for you — I know it's a very selfish thing. But then again, it's very cool to be able to entertain people."

As time went on, O'Hare learned to box without really thinking about it. She and Finney agree that the coach had a way of prepping her for bigger and better things, without always explaining everything he had in mind. "Girls are very emotional in and out of the ring — girls you date, girls you marry," says Finney, by way of explaining his understated approach with O'Hare. "And Jamie's...still a girl."

O'Hare had no idea what she was getting into with her first competitive boxing match, for instance. "I didn't really want to do it, but I didn't want to say no to Jesse," she says, explaining how she only came to find out it was a Golden Gloves title match after she'd won it. "I'm like, 'I get a belt?'"

Then there was the nerve-racker when Finney told her she had only a day to cut twelve pounds for her first international kick-fight, a barefooted match against a six-foot Hawaiian.

And the day Finney told O'Hare she was going pro. Recalls Finney: "It took her two days to get up the courage to call me and ask, 'Do you really think I'm ready for that?'"

His team had long ago nicknamed her "The Assassin." At the end of her amateur career, they rechristened her "All Heart."

At the O'Hare home in northwest Florissant, where Jamie still resides with Mom and Dad, boxing is a sensitive topic. Steve and Mary Ellen O'Hare, a chemical salesman and special education administrator, respectively, have always had somewhat more refined tastes when it comes to athletics. He likes to hit golf balls; she used to water-ski. Fighting is the last sport they would have chosen for their only daughter.

"We go to one of her first amateur bouts, and it's at South Broadway Athletic Club, where the ceilings were eight feet tall and every person in the room had two or three cigarettes lit. We're watching our poor daughter — who has asthma — get punched," Steve recounts.

"It made me nauseous," adds Mary Ellen. She walked out and didn't buy another ticket for two years.

Jamie was actually a "prissy" kid, her parents recall, popular in her teens and the founder of a high school club whose mission was to reach out and befriend the students who sat alone in the cafeteria. (Organized just months before the 1999 shooting at Columbine High School, O'Hare's club was memorialized in a long Suburban Journals article.) In college Jamie took up rock climbing, mountain biking and skydiving. "Having two brothers," notes Mary Ellen, "she didn't ever show fear."

Still, the O'Hares never expected to see Jamie throwing jabs and crosses. And the timing of her new hobby left the whole family feeling conflicted: From 2004 through 2006, Mary Ellen was engaged in her own fierce battle, with failing kidneys.

"She was so sick she would go to bed at 6 p.m., and sometimes I'd hear her crying quietly in her room," says Jamie. "I'm a fixer, and I couldn't do anything about it, so I used the fighting as therapy. But there were days when I felt like quitting. I was constantly thinking: How selfish can I be? She's sick and here I am doing something she hates."

Thirty people stepped up with offers to donate a kidney, but there were no matches, including among her family. "Jamie really wanted to donate, but she wasn't the right blood type," says Mary Ellen. "We even looked into the paired-exchange program, where she would've given an organ to somebody else who would've donated to me. That didn't work out either."

As for the boxing, says Mary Ellen, "we agreed to disagree."

Jamie learned to change her bloodstained clothes before leaving the gym for home, to spare her mother the sight.

Finney, her trainer, says he'll never forget those two years. "I try to keep my distance with fighters, but it was tough with Jamie," he says. "My mother is my best friend, and I don't think I could've handled that situation half as well as Jamie did. I admire the hell out of her for it."

On September 23, 2006, with Mary Ellen's kidney function hovering just above 10 percent of their capacity, the O'Hares at last got word that transplants were on their way from the East Coast.

"It wasn't long before I had my mom back," says Jamie. "And now she's 100 percent returned to her sassy self."

Mary Ellen concedes she's still not won over by boxing but is taking her daughter's battles as they come. On March 7, she arrives at the Ultra Sports Lounge in Union Station for Jamie's weigh-in toting the requisite Dairy Queen ice-cream cake. Jamie has texted and called several times to explain how friendly Carrine Hamlett seems, and Mary Ellen is anxious to meet her daughter's rival.