Andrew Machin ... public servant by day, MMA fighter by night.

Andrew Machin ... public servant by day, MMA fighter by night. Photo: Colleen Petch

By day, Canberra's Andrew Machin is locked to a desk as a public servant.

By night, he's locked in a cage, the 114-kilogram fighter trying to beat his opponent into submission.

The public service is well known for it's acronyms, but MMA - or mixed martial arts - isn't generally among them.

Andrew Machin.

Andrew Machin. Photo: Colleen Petch

But Machin, a 15-year veteran of the public service, will get his shot at a national title in Canberra on Friday night when his heavyweight bout headlines Brace for War at the Canberra Convention Centre.

Having notched up a record of six wins and two losses, Machin will step into the cage for the Brace interim heavyweight title. Machin is on Christmas leave from his job, so at least he won't have any explaining to do after his bout with knockout machine Felise Leniu of Sydney.

''Some guys play football or go hang gliding or people ride horses or motorbikes, everyone's got their thing they do and I guess [MMA is] mine,'' he said.

''It's a sport that isn't for everyone, and I understand that.

''Sometimes you come in [to work] with scratches, bumps and bruises and things like that. People … if they don't know they tend not to ask, I guess.''

Machin took up MMA, the sport also known as Ultimate Fighting, two years ago as a progression from years of boxing and Brazilian jiu-jitsu.

''I'd trained a lot and watched a lot of fights, and I'm not young, I thought if I ever want to do this, it's probably the best time. I saw it as an opportunity to test my skills,'' the 37-year-old said.

Machin continues to train in multiple disciplines - boxing, jiu-jitsu and MMA - but if he has a signature move, he's not giving it away before fight night with Leniu.

''You need to be as good as you can be in all sorts of areas,'' Machin said.

''I try to do my best in all of them and just chip away

''I haven't fought him [Leniu] before, I've seen him in other shows … it will definitely be my hardest fight to date, he's knocked a lot of people out.

''It will be a big test for me, I'm looking forward to the challenge and I'll have to be on my game, but I wouldn't be getting in there if I didn't think I could win.''

Friday's card will feature 12 bouts.