ABC News' Producer Angel Canales and Editor Arthur Niemynski report:

SAN DIEGO - Growing up overseas while her father was in the Air Force stationed in Okinawa, Japan, Liz Carmouche was surrounded by military life from early age. "The people in my life that I looked up to the most were Marines and they were everything I wanted to be," says Carmouche.

Carmouche joined the Marines in 2004 to find some direction in her life. She served for five years and became an aviation electrician on the Boeing Vertol CH-46 Sea Knight Helicopter, serving three tours in Iraq. During her time in the Marines, Carmouche never wanted to be the weakest link. "I was always a gym rat. I was always wanted to be in the best shape. I always wanted to make sure that within my unit that I was never the weak person. So I made sure that my physical fitness was top," says Carmouche.

When Carmouche left the military in 2009 she joined a gym and that's when she heard about Mixed Martial Arts. She was intrigued and began training. "It was difficult. I jumped in from day one and I did every class that they had," she says.

For Carmouche, now a UFC Bantamweight fighter, the path to her career was clear. "For me it has been relatively easy. I know other people struggle. They start with one martial art and change but I just dove in and for me I think it is what I was supposed to do. All the pieces fell in the same place at the same time and if anything had changed, I wouldn't be where I am today," she says.

With her 8-4-0 record in the Ultimate Fighting Championship Bantamweight division, Carmouche has fought tough competitors including women's bantamweight champion Ronda Rousey and holds wins over Jessica Andrade, Jan Finney and Kaitlin Young. She says her first MMA bout was bloody and messy. "First time going in I was sparring professional guys that had titles and I was thrown in there and my coach said; 'Hey is this something you really want to do?' Came out all bloodied up, clothes torn, messed up, just dripping sweat, but I knew it was something I wanted to do," she says.She immediately found the affirmation she needed. "I figure if I can take it from these guys who are supposed to be the best, then I knew I was in the right place," says Carmouche.

Will power has proven to be Carmouche's key to success. "I'm constantly pushing myself to evolve and be a better person and the best that I can be and that pushes me in my fighting career and personal life," she says. She has made history as the first openly gay fighter in the UFC. "For the most part everybody has been very accepting. They knew when I came into the UFC that I was already open and I was already out. I made sure that after I got out of the Marine Corps and having to stay in the closet during Don't Ask Don't Tell policy that when I got out that that was something I will never go through again. That was not the person I wanted to be," she says.

Staying true to her identity is important, she believes. "I think a lot of people struggle when they get out of the Marine Corp because they don't know how to be a person. They only remember how to be a Marine and they don't know how to transition into the real world. I made sure that every moment that I had I was Liz again and I remembered who that person was," she says. And finding Mixed Martial Arts and a place where people accepted her made the transition easier, she says.

Carmouche's goal is to be number one in the world. "I'm gunning for the title. I'm going to be the champion and that's what I aim for. To be the best of the best," she says. Her message for veterans: "The military gives you a safety net. They give you guaranteed medical, guaranteed food and a place to live. If you have a dream put everything you have into it and follow it because that's the only way you'll have success in your life."

Her message for veterans:

"The military gives you a safety net. They give you guarantee medical, guaranteed food and a place to live. If you have a dream, put everything you have and follow it because that's the only way you'll have success in your life."

Second Tour is an ABC News digital series profiling the lives of military veterans who are doing unique things in the civilian world, including vets who took on an entrepreneurial venture to create a business, grassroots organization or a second career. For more stories visit https://abcnews.go.com/US/Second_Tour/.