BBC Sport is paying tribute to pioneering women in sport in the run-up to International Women's Day on 8 March. Here, three women who have refereed men's sport in snooker, rugby and football share their experiences.
First woman to referee World Snooker Championship final - Michaela Tabb
Tabb is a former pool player and referee who has officiated at two World Snooker Championship finals, the first woman to do so.
"I was a nine-ball pool player and started refereeing pool matches when I was pregnant with my first son.
"World Snooker had taken note and, unbeknown to me, there had been a little bit of chat going on because they wanted to change the profile of their refs at that time.
"They wanted to change the image, bring some younger refs in, bring a female in and there was me out there flying that flag.
"My husband and I talked about it because it was a big thing for me to go away because my son was only four at the time.
"But we saw it as such a big opportunity that it was too good to turn down and we thought we will give it a shot and if it doesn't work, it doesn't work. At least we tried. And off I went.
"I was fast-tracked through the system and there was certainly hostility from some of the established referees at the time.
"But it lit the fire under me, because I thought, I'm going to show you. It really motivated me and was actually the best thing that could have happened because it made me work so much harder to be the best and never make mistakes - not that I never made mistakes but that was my aim.
"I found out I was refereeing the World Snooker Championship Final in 2009 and I spent the whole week panicking but when I walked out it was unbelievable. It was one of the greatest moments of my life.
"There have been downsides and in 2013 I had to warn Ronnie O'Sullivan for making an obscene gesture with his snooker cue.
"Ronnie did admit it afterwards but you should see the flack I took on Twitter and Facebook. I have never been so abused by some real die-hard Ronnie supporters that don't see past the fact. They said I made him miss the next shot- rubbish!"
Ireland's top female rugby referee - Helen O'Reilly
O'Reilly is the first woman the Irish Rugby Football Union (IRFU) appointed to its National Referee Panel. She also officiated at the 2014 Women's Rugby World Cup.
"I played rugby for about 13 years and when I retired I wanted to stay involved in the game so it was either coaching or refereeing.
"I started off refereeing a lot of junior rugby and women's games but you get assessed and if you're good enough, get promoted up the leagues.
"Fortunately, I got promoted quite quickly through the ranks and I was taken on by the Irish Rugby Football Union and that's when I started to go on to the national panel.
"I used to pull up in the car park and men's teams would think I was the physio, and they would point me to the physio room, that happened on a regular basis.
"But my profile has built a little, so they now know who I am when I show up.
"I've never had an issue with the lads on the pitch but they know that they've got to work with me for the next 80 minutes, so it's fine.
"I can't go out on the pitch and show any fear at all, with guys 6ft 8ins and 6ft 9ins, I can't show any fear.
"If I thought of myself any different as a female official I was going to be lost, so I have to go out there, hold my head high, shoulders wide, and referee the game like any of my male counterparts.
"There were a few question marks in the Women's World Cup about the standard of refereeing but I think it was great that it was an all female panel.
"I do believe that we have to keep pushing ourselves to improve the standards though as the game itself has improved from where it started a few years ago, and I think that the refereeing has to come up to that standard as well.
"If I don't perform this week I could be dropped next week, so I take it game by game. I could eventually officiate Guinness Pro 12 and Heineken Cup matches but the National Panel of Ireland and the Women's World Cup again are my goals for the next couple of years."
Former football referee - Janie Frampton
Frampton is a former football referee and became one of the Football Association's national referee managers. She now runs a sports officials consultancy.
"I started playing football at the age of 15. I then had children in my early twenties and I wanted to get back into it, but there were no opportunities playing and the only way I could get back into it was to be a referee. So I took up refereeing and it went from there really.
"I got to professional football level. I was the second woman to reach that level behind Wendy Toms, who was an excellent friend, role model and mentor to me over the years.
"In 1999 Wendy and I, along with Amy Fearn, became the first all-female officials at a men's [professional] game, which was Kidderminster against Nuneaton in the Conference.
"The pathway for women then was different, no-one knew what to do with us. Over the years, it's come an awful long way. We have a long way to go, but women are starting to become equal in that environment.
"I believe we will have a woman refereeing in the Premier League when we have one good enough and I still think that will be some years away.
"One thing I would never want is to have positive discrimination which means they get the job just because they are women.
"They have to manage that expectation and live with their peers and their peers will know that maybe they've got there because they are women. I know, 100%, that the women we do have currently at a high level are there because they are good enough.
"Women face different challenges than men do. We are looking at it with Sian Massey now. Sian is having to put her career on hold as she is having a baby. Amy Fearn has had two children and she has been the most amazing role model for coming back and retaining her fitness.
"We still have incidents of sexism and it's about education. It's about changing mindsets. Football is predominantly male, the decision-makers are predominantly male and until we can make a difference at the top to cascade down, it will be difficult to change those mindsets.
"But I know that the Football Association are looking very seriously at the demographics of people at a high level and we just hope that will make a difference, cascading throughout all football."