06/11/2013 03:57 EDT | Updated 08/11/2013 05:12 EDT

Brainiac turned cage fighter: Rosi Sexton can break you, then help fix you

Lawyers, engineers, teachers. There has been no shortage of brainiacs fighting in a UFC cage.

But Rosi Sexton may have raised the bar when it comes to MMA fighters' education. The 35-year-old Sexton has a degree in mathematics from Cambridge, a PhD in theoretical computer science and a degree in osteopathy.

She can break you, then help fix you.

On Saturday, the brainy bantamweight from Manchester becomes the first English woman to fight in the UFC when she takes on Canadian Alexis Davis (13-5) at UFC 161 in Winnipeg.

"I would never have imagined growing up that I would be a professional athlete," said Sexton. "In fact, if you'd said that to any of my classmates, they would have laughed at you. I was the nerdy kid who didn't particularly get on with sports at school.

"But I can say it's been a hell of a journey."

Sexton, a pioneer in the women's side of the sport, made her pro debut in May 2002. She saw a posting on a forum asking for a female fighter but, by the time she got in touch with the promoter, they had found someone.

Sexton got a call a few weeks later.

"The girl's just pulled out, do you want to fight? It's tomorrow," she was told.

She had never been in a full-contact fight and had only done limited sparring in training.

"But at the same time I didn't know when there was going to be another opportunity, because there was so little of it going on," she said.

So she took the fight, winning by a first-round submission.

Eleven years and 14 fights later, Sexton finds herself entering the sport's biggest spotlight. Having spent most of her career fighting at 125 pounds, she wasn't sure if the UFC's decision to open the door to female 135-pounders was for her.

But she sat down with her team and asked whether she could fight at 135.

"We decided it was too good an opportunity to turn down .. It's something that I want to be part of," she said. "Especially at this time in history, when women are just starting to get involved in the UFC, it's a fantastic time to be involved in all that and to be making history."

Sexton, listed at five foot three, went on a strength and conditioning program to add on some pounds.

It worked. She weighed as much as 147 pounds going into camp and will have to cut weight to make 135.

Sexton's two career losses came at different weights.

She was supposed to face Gina Carano at 135 pounds, only to have Carano show up at 139. Sexton lost the September 2006 fight by second-round knockout.

"The Carano fight, I was definitely too small," Sexton said. "I'm considerably bigger and stronger now than I was then ... My game's changed considerably as well, I'm a very different fighter now than the one I was going into that particular match."

Her June 2010 loss to Zoila Gurgel in Bellator was at 120 pounds.

"It was one of those (fights) where everything was going great and then I woke up," said Sexton.

She dipped her head at the wrong time, catching a Gurgel knee that resulted in a first-round knockout.

Sexton, who has an eight-year-old son named Luis, calls herself a full-time athlete and part-time osteopath.

"One and a half jobs as well as being a mother," she explains.

Luis has grown up around MMA but Sexton says he's more interested in soccer than fighting these days.

"He's at the age at the moment where I think he thinks it's quite cool what his Mum does," Sexton said. "He enjoys telling his friends that his Mum's a fighter, which means I get some interesting looks from the other parents and teachers at the school."

Her interest in osteopathy came after she received treatment for a back injury sustained during judo training.

"I was really impressed with what he did. That was when I thought, 'Right I need to be able to do this.'"

A few years later, she decided to make treating sports injuries a career. Five years of part-time studying later, she had the degree to back it up.

Sexton's road to MMA started at 14 when she took a taekwondo class. Its started as a way of learning some self-defence, but she soon found she liked it.

"It was the first time I found a physical activity that I really got a buzz off, that I really enjoyed doing."

At Cambridge, she tried her hand at a few different martial arts: including judo, and traditional jiu-jitsu.

Then a few years later, while she was doing post-graduate work, she saw a documentary about mixed martial arts.

"As soon as I saw it, I though that looks like a fantastic thing to do, that looks like a great challenge," she recalled.

"Obviously once I started training specifically for that, started doing the grappling and all of that, I realized how much I didn't know so that added a whole new element to what I had to learn," she added.

Fighting has taken her around the world, from a beachside ring in Costa Rica to Las Vegas, Vancouver and St. Petersburg, Russia.

"I've had the opportunity to be involved in some great events, some I suppose really fantastic and in a way quite surreal experiences, the sort of thing that I never expected to be involved in," she said. "When I first started out in the sport, my original plan was 'Right, I'm going to have a couple of fights, I'm going to prove to myself that I can do it and then I'm going to get on with my life and go work in an office or whatever.'

"And I had a few fights and I found that I was actually reasonably good at this. Then I started thinking 'Well how good could I get, if I really focused on it? Could I be one of the best in the world.'

"And I suppose, 10 years later, I'm still here."