“Words like ‘feminine’ and ‘fighter’ can go together,” Garbiñe Muguruza says with charming force on a cold but sun-kissed morning in Madrid. “You can be feminine and you can say, ‘I really want to beat her. But I don’t want to look like a little monster in the corner.’ I want to take this wall down which says you are one thing or the other. If you are a feminine athlete people say: ‘Oh, she wants to be a model or she’s not concentrating.’ No. We are concentrating.”

Muguruza, the reigning Wimbledon champion and world No 3, is a formidable competitor who is proud she beat Serena and Venus Williams in the finals of the two grand slam tournaments she has won so far. In a ridiculously stylish hotel she is also relaxed and refreshingly forthright.

“It’s a delicate thing because for some people it’s very hard to allow an athlete to be feminine. For me it’s easy. I want to fight on court but I also want to wear something I like. You can be angry and competitive and a fighter and you can also be nice and wear something by Stella McCartney. I feel good in that and it’s important for your esteem because you’ve got to be resilient. I’m a tennis player, and that’s my priority. I like fashion but I would never want to be a model. I don’t want to forget what I’m good at because as soon as you do you’re screwed.”

Novak Djokovic faces uncertain future after struggling in year of pain | Kevin Mitchell Read more

The 24-year-old Spaniard, who was born in Venezuela, smiles at that blunt truth as the clay court season gathers pace with the Madrid Open starting on Sunday. And when Muguruza tells me about being invited to the Oscars in March, she ensures that the most telling line is one where her concern for ordinary woman is obvious. “I wore black,” she says, in honour of the #MeToo movement against sexual assault and harassment, “but it wasn’t like the Golden Globes where everybody wore black. It’s a problem that was quiet before but it was there all the time. It got more exposure because the women who spoke out are famous and it’s Hollywood. If an Oscar winner speaks about it then it goes everywhere. But if the waitress says this has happened to her nobody really listens.”

The impact of that last sentence is powerful – and Muguruza nods calmly. “It’s everywhere.”

Hollywood, obviously, is not the real world but did she enjoy the Oscars? “At the beginning I was like, ‘What the hell am I doing here? I’m not part of this world.’ You see all these glam celebrities and it’s a place to just be good-looking. It was also long, like a six-hour ceremony, but I had fun. I went to a Vanity Fair party and met [the basketball great] Kobe Bryant. Normally it’s not my kind of thing to take the phone out and say, ‘Can we take a picture?’ But this was Kobe and he’d just won an Oscar [for Best Animated Short]. He was very nice and let me hold the Oscar and it was so heavy. But he was so calm, I was impressed.”

Muguruza also met Billie Jean King, whose defeat of Bobby Riggs in 1973 has been turned into a Hollywood film. “I want to see it because I heard it’s good,” Muguruza says of Battle of the Sexes, which captures the way King took on Riggs and sexism. “But, usually, when I watch a movie I want to see Fast and Furious or the Expendables. I just want to chill out, turn up the volume and stare at the screen.”

Facebook Twitter Pinterest Garbiñe Muguruza after her women’s singles final victory over Venus Williams at Wimbledon last year. Photograph: Tom Jenkins/The Guardian

She laughs at her terrible taste in movies before acknowledging the debt all female tennis players owe to King and another pioneer for equality in Venus Williams. Women now receive the same pay as men in grand slam tournaments. “I speak to other athletes and they don’t have the impact, the money and equality we have. It’s getting better and better in tennis and hopefully it can soon be completely equal in all tournaments. But in other sports it’s not like that.”

Muguruza won £2.2m after beating Venus Williams in the Wimbledon final last year but the tennis circuit, particularly for lower-ranked players, is testing. “Tennis is very lonely,” she stresses, “especially when you are younger and don’t have family around. It can just be you and your coach in China. But everybody is in the same situation. You have to be a young old lady – that’s how I call myself sometimes. You have incredible moments and very bad moments when you are alone. You miss your family but tennis just lasts for a short period. You make sacrifices but I don’t miss having a young life. I’m happy and very privileged.”

Sign up to The Recap, our weekly email of editors’ picks.

Four years ago, at the French Open, Muguruza’s full power was revealed for the first time when she gave Serena Williams the worst beating of her illustrious career in the second round. “It was an incredible match nobody was expecting. If you told me before I was going to win 6-2, 6-2 I would be surprised. But I never stopped believing I could beat anybody – even if Serena is one of the best players in history. She was one of the women I watched on TV as a kid.”

In 2016 Muguruza won her first grand slam, at Roland Garros, when she again beat Williams in straight sets in the final. “I was nervous because I had made the 2015 Wimbledon final but it only matters that Serena won. Yeah, I played well but who cares about the loser? So in the French I was like, ‘I don’t want to lose again.’ I was also motivated because beating a Williams sister has extra value. If you win a grand slam by beating them it feels more important. It was an explosion of happiness.”

Last year was much more difficult in Paris when, in the fourth round, she lost against the local favourite Kristina Mladenovic. Muguruza’s errors were cheered and she left the court visibly upset. “The crowd was very involved and with her. It’s normal. But I had tears in the press conference and showed people how athletes feel. Some people were surprised but I’m like: ‘Come on, I’ve been three hours on court and it’s emotional. That’s what everybody does in the locker room but you don’t see them.’ It was good in the end because I expressed myself and showed I am human. The French Open will always be the most special tournament to me. It was my first grand slam and the tournament I wanted to win when I was little.”

Winning Wimbledon was thrilling last year. “I was emotional because when I lost to Serena in 2015 I didn’t know if I’d get another chance as grass is unpredictable. So to beat Venus and win it two years later? I was like: ‘Whew!’”

Muguruza, who jokes about her serious salsa dancing, was mortified at the Wimbledon dinner. “People had told me, ‘There’s a ball and you can dance.’ I’m like, ‘Oh my God I’m going to dance with Roger Federer? Yes, I’m ready for that.’ Then someone told me there’s not a dance since 1992. ‘What?’”

Muguruza opens her eyes in horror before smiling. “A ball for Wimbledon is serious, elegant, classy. You can’t do the conga but I was ready for everything!”

She has a chance of winning both the French Open and Wimbledon again this year – because she clearly raises her game in major tournaments. Her recent tour win in Monterrey gave her a sixth WTA title – but there was a time when her four tournament wins included two grand slams. Her inconsistency almost amuses her.

Facebook Twitter Pinterest Muguruza in Fed Cup action for Spain against Paraguay earlier this month. The French Open on clay will be one of her main targets for 2018. Photograph: Quality Sport Images/Getty Images

“Everybody asks about Eastbourne before Wimbledon last year. What a disaster. I lost 6-1, 6-0 [against Barbora Strycova] and then won Wimbledon. What is this? But I had played a very good Birmingham tournament and I ran to Eastbourne and it was a crazy day. I played awful and she played good. I was like, ‘OK, nobody saw this match.’ Everybody loves that. ‘You lost 6-1, 6-0 and then you win Wimbledon? What happened?’ Nothing. It was just a bad day. I’m happy to not have any WTA titles but to have one grand slam.”

Beyond her drive to win the most important titles, Muguruza’s rounded attitude means she has begun to explore her interest in fashion design. “My mum and I always talk about it because her dream was to be a designer. Of course I’m always wearing sports clothes so, even more, I want to wear high heels. I’ve now started to do some designs. I take my tablet when I’m travelling and I look at magazines and make notes. Then I design the way I like.

“It’s good to escape because since I was very young everything has been tennis, tennis, tennis. Now I have more perspective and space in my head. I take a few hours to do something fun for myself. It’s healthy. So when the time is right it will be OK for me to close this chapter on tennis. I’ll probably have a family and do something related to fashion.”

Her ease in front of the camera is obvious when she slips into the hotel garden for the photo shoot, but Muguruza is fiercely competitive and says: “I also fear the end because tennis is a life. I’m happiest when I win. You enjoy not knowing if you’re going to win and you can love hating the court.”

Muguruza, a feminine fighter and a champion, breaks into a helpless smile. “When you shake hands, and think, ‘Yes, I won,’ that’s such a good feeling. All the hours of training feel worth it. So the best moment is when it’s over and you’ve won.”