How does it feel to be ranked No 1 in the world?
It brings me immense happiness and makes me proud. I joined a succession of truly great champions.

What sacrifices have you made to attain such success?
When I was 12 I went to the Nick Bollettieri Academy in Florida. I was away from my family and friends for the first time in my life. I didn’t know anyone and couldn’t speak English. It was difficult.

Your mother accompanies you on your tennis travels. How important is that?
It’s impossible to say how important she is to me. She’s my best friend, my most dedicated supporter, my most trusted confidante. All players need somebody to turn to when times get difficult.

Was tennis your first choice of sport?
When I started to play tennis it was my choice and nobody else’s. I found myself getting better and better and now here I am.

What is it like for you when you go home to Serbia?
Serbia is a small country but has produced three of the most well-known names in tennis - Novak Djokovic, Ana Ivanovic and me. The people are proud of us and tennis has become the most popular sport in Serbia.

What do you do for relaxation?
For just an hour or two I maybe read a book or listen to some music, but I love the weeks away from the tour. I love going on vacation to some exotic place where I can relax, enjoy myself and forget about tennis.

It’s said that you and Ana Ivanovic don’t know each other too well. Can you have best friends on the tennis tour or is everyone a rival?
Ana is two years younger than me so we didn’t really play each other as juniors. We get on fine now and play in the same Fed Cup team for our country. It’s not difficult being friendly to the other girls on the tour when we are away from the tennis courts but of course anyone across the other side of the net is a rival.

Everybody in Britain remembers you for that very happy mixed doubles partnership with Jamie Murray at Wimbledon in 2007. How much did you enjoy the experience and how important is a mixed doubles title when you are really intent on the singles crown?
Jamie is such a nice guy and that was such an enjoyable few days but I honestly can’t say I expected to win the title because I am not a very good doubles player. We had never played together before and that was the last time I took part in a mixed doubles competition. To have a Wimbledon title to my name is great but singles is now my main priority.

Who has been the most influential figure in your career?
My mother, for all the reasons I’ve already given. She is such a cutie and is always there for me in both the good and the bad times. But I suppose the player who I idolised most when I began playing tennis was Monica Seles, because she was such a sensation and came from my country.

How regularly do you feel the need to throw off the tennis clothes and tracksuits and glam up a bit in a smart dress?
Every day. As soon as I leave the tennis site and fulfil all my obligations, I put on heels and jeans and fun clothes. I’m just a normal girl who loves clothes and dressing up. I’m not the sort of person who likes hanging around in tracksuits and tennis shoes if I’m finished with all my work.