Third seed Karolina Pliskova is among the favourites to win the women's singles at the US Open and will play Tunisia's Ons Jabeur in the third round on Friday.

In her latest BBC Sport column, the Czech discusses her relationship with twin sister Kristyna, who is also a WTA Tour player, how they shared a hotel room before they played each other in Birmingham recently and what she bought Kristyna for beating her…

When the draw for a Grand Slam tournament is made I'm always worried that Kristyna and I will be drawn against each other in the first round - that would be the worst day of my life!

There would be too much pressure and too many nerves because the Grand Slams are so important and mean so much to us.

So it is always a relief when my sister is in the opposite half.

That's what happened here at the US Open, although it was sad that she lost to Elise Martens in their second-round match on Thursday.

We don't watch the draw as it is being made, nor do we follow it on social media, and then when we do eventually see it we message and always say: 'Phew, we are not playing each other!'

We have only played each other once on the WTA Tour and that came a few months ago in Birmingham.

It was a very difficult situation for both of us - and the worst thing was that we were sharing a hotel room at the tournament!

We have played each other many times when we were younger - in qualifiers and on the lower-ranked tours - but we hadn't played for about six or seven years.

We had come close a couple of times in main draws but either I lost or she lost earlier, and also I had to withdraw once because of injury when we were supposed to play in Prague.

So it felt like everybody was waiting for this match to happen, the Czech media were excited and many people were talking about the match.

'Our parents couldn't watch'

It was a strange atmosphere in our hotel room on the morning of the match.

Kristyna and I were trying to be calm and act normal, but all the people around us and our teams were stressing and wanted to talk about it so much.

Thankfully our parents weren't there in Birmingham, I can't imagine how horrible it was for them. They didn't even watch on television back in the Czech Republic.

My mum doesn't usually like to watch our matches anyway because she is too nervous. My father usually does watch matches - but not this one. He did something else to take his mind away from it.

So we both felt very nervous and didn't know what would happen, if we would play good tennis or bad tennis.

It was huge pressure for me because if you look at the rankings I should win easily.

Of course I wanted to win the match, but I also didn't want my sister to lose. It was an emotional rollercoaster. We ended up playing a long match and Kristyna won 6-2 3-6 7-6 (9-7)!

It was the biggest victory of her career - she had never beaten a top-five player before that.

Kristyna is ranked 86th at the moment but I believe she has the ability to improve that a lot. She is not easy to beat.

If we could both be ranked in the top 10 together that would mean a lot to both of us - even more to her of course - and our families.

But that would also mean we would play each other even more, which is something I'm not sure I would enjoy!

Maybe it is something you could get used to if it is happening more often, and then we wouldn't be as super stressed about it like we were in Birmingham.

'Sometimes I talk to Kristyna more than my husband'

Of course we look similar because we are identical twins. However, I think we have aged a little differently, and we try to be different because we have never wanted to be the same.

We have different tattoos. She is a little more blonde. And our personalities are quite different.

But sometimes we think in the same way, and we often say the same thing at the same time - that makes people laugh.

She thinks a little more about stuff and is more responsible. She is two minutes older - so maybe she is trying to be like the boss a little bit and protect me!

We still give each other advice about tennis; we give advice to each other about everything in life.

Barely an hour goes by when we aren't talking on the phone - I text "hi" as soon as I wake up and and we continue all day on WhatsApp.

Sometimes I speak to her more than my husband! He doesn't mind though and he's happy for Kristyna to hang out when it is just the three of us.

The week before the US Open we went to watch some Broadways shows together - Pretty Woman and Frozen - and had a few dinners, and also did some walking and shopping.

With us being in different parts of the draw - I played Monday and Wednesday, and Kristyna played Tuesday - we have not done much in the past three or four days because you don't want to go into Manhattan and waste energy.

I need all my focus on going as far as I can in the tournament and hopefully winning my first Grand Slam.

Karolina Pliskova was talking to BBC Sport's Jonathan Jurejko at Flushing Meadows