If you were to pinpoint the defining moment for women's football in the UK, you will likely go back to July 31, 2012.

A crowd of 70,584 descended on Wembley to watch Team GB beat Brazil 1-0 in a game that has long been remembered by those who played that night.

For Kelly Smith, who was Britain's most recognisable player at the time, it was an occasion that marked a significant turning point for the sport.

'You pinched yourself as you walked out and thought "wow, this crowd is for us", it gave you goosebumps,' Smith tells Sportsmail.

'It was really surreal because, as a female footballer growing up, you only ever dreamed of playing in the World Cup and European Championship because they are the two main tournaments that England could go for.

'It was never a dream to play in the Olympics because there wasn't a GB squad. It was a brilliant opportunity to experience and you got to come out as an Olympian.

'That's where it started for women's football in terms of exposure - 2012 was the catalyst and the game has really kicked on from there.'

While Smith was one of the household names in the squad, it was her then Arsenal team-mate Steph Houghton who took the headlines throughout the tournament.

Age: 20

Club: Manchester City

Kelly's verdict:

She's been absolutely outstanding, her performance against Chelsea in the 2-2 draw recently, she got me off my seat with her work-rate, her energy, her movement with the ball.

The way she dribbles and can move and manipulate the ball with her body to beat players. I haven't seen that excitement in a player in a long, long time. She's only young and it's whether Hege Riise gambles on that inexperience.

She's not unknown here because people have been seeing her and watching her but she's probably unknown on the world stage.

The defender scored in each of the three group games, including the goal that gave Team GB a historic 1-0 win over the Brazilians.

'What's funny is she was playing out of position at left back,' Smith recalls.

'She was versatile because we had two centre halves at the time who had solidified those spots so she was playing at full back which isn't her natural position.

'To be the top scorer at left back was unbelievable. That was when she came to the forefront of people's minds and people knew who she was.'

Team GB had not been expected to beat Brazil, who had a star-studded line-up including six-time FIFA Player of the Year winner Marta, and their 1-0 victory raised hopes that they could go on to pick up one of the medals on offer.

It felt like a missed opportunity, therefore, when Hope Powell's side were beaten by Canada in the quarter-finals.

'I personally think the Brazil game zapped our energy a lot because of the experience of it and the occasion,' Smith admits. 'I don't think we were really at the races for the quarter-final against Canada.

'I didn't play in that game, I picked up a dead leg. I remember Hope saying, "once we beat Canada, you'll be fit for the next game" but I think we took them as if we were going to beat them and we just didn't perform.

'I think in hindsight we probably should have rested some players against Brazil once we went 1-0 up to keep them fresh.'

That Olympic Games was the first time a British women's football team had taken part in the tournament. There was no agreement reached by the Home Nations to enter a team in 2016 but a deal was formed for Tokyo, with Team GB qualifying after England secured one of the top three European places at the 2019 Women's World Cup.

Smith is hopeful that Hege Riise's squad can learn from the past and believes they have a realistic chance of winning the tournament.

'I do (think Team GB can win). I look at the England squad in terms of Fran Kirby and Lauren Hemp - players that are in really fantastic form right now and in peak condition. Hopefully they can do that in tournament football.

'There's going to be some names that don't make the team where you'll be thinking "wow, they could have made an impact". I think Hege Riise has got a really tough squad to pick from. The talent that she's got is incredible.'

Smith is one of three former Olympians to have helped launch the 'Energy Fit for the Future' campaign by Smart Energy GB.

Mr Motivator set Smith, long jumper Greg Rutherford and boxer Nicola Adams a series of sporting challenges using old equipment to illustrate that you can't perform at your best if you're using outdated technology.

Smith was tasked with getting a hole in one using a hickory golf club, Adams had a tennis match with an old racket, while Rutherhad had a race on a penny-farthing.

'We really noticed that using the old equipment was really hard and difficult,' Smith says.

'It looked really difficult watching Greg get up on the penny-farthing and then how easy it was just for him to go up on a normal track bike. You just can't perform to the best of your ability without the latest technology.

'Using a smart meter, it enables you to move with the time and have a more clean energy.'

'We realised that using the old equipment was very difficult but when you have new equipment it's easier for athletes to reach the top of their game. It was interesting to put the analogy of both together.'

Smith is hoping Team GB's progression to the knockout stages is less of a challenge but it will not be straightforward for Riise's side with hosts Japan, old foes Canada and Chile making up the rest of Group D.

'Japan is always going to be a tough game because they've been preparing for this for donkey's years,' says Smith. 'Canada is always a ding-dong match between the two nations - England and Canada that is.

'Chile are an unknown really but we saw them in the World Cup perform to high levels. I don't think England have played them recently or possibly ever so they're an unknown entity. They'll be three very tough games but I do expect them to get out of the group.'

The question on everyone's lips, however, is can the USA be stopped? They have won the last two Women's World Cups and won gold in 2012. While they were knocked out by Sweden in the quarter-finals in 2016, that will have only made them more determined to win at Tokyo this summer.

'I think they can be stopped, we saw how close England got to them in the last World Cup. It was small margins, we understand how tight the games are,' says Smith.

'The attacking array of talent that we have in this country now, you've got match-winners and game changers - we've never really had that in previous years.'

Kelly Smith is part of the Get Britain Energy Fit For The Future campaign, encouraging everyone to do their bit to help modernise our outdated energy system by getting a smart meter – paving the way for smarter homes and more integration of renewables.

Read more at www.smartenergygb.org/energy-fit-for-the-future