CINCINNATI, Ohio - Kiki Bertens is a clay-court specialist no more. The 26-year-old became the first player from the Netherlands to win the Western & Southern Open, where she defeated four Top 10 players, including World No.1 Simona Halep, 2-6, 7-6(6), 6-2 to win the biggest title of her career. 

Bertens will rise to a career-high No.13 when the WTA rankings are released on Monday, and her Cincinnati run surges her up the Porsche Race to Singapore Leaderboard at No.7. Since leaving her most favored surface of clay, Bertens has won eight consecutive matches against Top 10 opposition, including six such wins on North American hardcourts. In addition to earning her first win over  reigning No.1 on Sunday, Bertens has also scored big wins over Petra Kvitova (the tour-leader in titles), Caroline Wozniacki (the reigning Australian Open champion), Elina Svitolina, and Karolina Pliskova. 

And to think: Kiki Bertens considered walking away from the sport just 10 months ago. 

Bertens joins the WTA Insider Podcast to discuss her career-best season, her newfound hardcourt prowess, and why she thought about quitting the sport after her 2017 season.

Listen to the full interview on the new episode of the WTA Insider Podcast below:

WTA Insider: Kiki it's been an incredible two weeks for you. This week alone, you beat four Top 10 players to win the title. You beat the World No.1 in Simona Halep and World No.2 Caroline Wozniacki to win your first hardcourt title in your first hardcourt final. What you've accomplished the last two weeks is absolutely astounding. How do you feel right now? 

Bertens: Yeah it's unbelievable. What you're saying right now I cannot really believe it, that I did all that this week and today as well, but I'm really proud of myself that I could do this.

WTA Insider: Let's start with just talking about your coach, Raemon Sluiter. You guys have been working together for about three years now. I know that it's not always been rosy and sometimes it's been tough working together. But can you talk about your relationship with him and what he has been able to kind of pull out of you as a coach to level up.

Bertens: He helped me see that I had to put a lot of hard work in. Every year I'm improving. I'm improving my fitness as well. You really have to work hard to get better and I think at every moment he's trying to do that. 

We had a little talk earlier this week where it was not always like really nice but he just everyday, he wants to improve and that's a really nice thing about that and that's why I'm really happy to work with him.  

WTA Insider: What are the some of the toughest messages you've had to hear from him.  

Bertens: Sometimes it's frustrating because I have to do a little bit more, like maybe watching my games or focus a little bit on this more, and sometimes I think, Oh, but I'm doing a good thing right? And I'm really doubting about myself. Like when he's saying something my first reaction is, Oh, so I'm not doing good? So I'm more negative and he's like really positive, so I have to see the good things in that. But yeah at the end of the week it's working.  

WTA Insider: Obviously the clay season was great. You made the biggest final of your career in Madrid, you won Charleston. Then on grass the Wimbledon quarterfinal, which was amazing. Now the last couple of weeks, with all the wins and then now culminating in this title the biggest one of your career, what has been the standout moment for you? 

Bertens: I think it's just a little bit of everything. That I can continue to play like this, that it's not like only one moment that I'm really peaking. Normally it's only the clay court season. Now there's also the grass and now the hardcourts. It's such a great feeling that you don't have to be peaking at only one moment a year. Now it's everywhere. I think that's the thing I'm most proud of, that all the work is paying off. 

WTA Insider: We've spoken in the past, especially after the clay court season, about feeling the pressure of defending your clay points. With the success outside of clay you don't have to worry about that anymore. How much does that free you up? Even coming to the hard court season this year, of knowing you're playing with house money. 

Bertens: Yeah it was really relaxed going in this US season I was like, okay every match is won and it doesn't matter because last year I almost lost every match. It's just a great feeling that you can only win. And that's what we went for. I like to play as many matches as we could. Then you play one quarter finals already in Montreal and you have one title here, and there's still a lot of tournaments to come. So I am really looking forward through the rest of the season. 

WTA Insider: Was there a win that you've had over the last two months since the clay that had more impact on your belief and your confidence than other wins?  

Bertens: I think in the grass court season when I won against Venus and also against Pliskova, making the quarters there in Wimbledon. It was a great feeling. Also in the past two weeks, I think just continuing that level. And I think today was such a big moment to win for the first time against No.1, to win my first hardcourt title, I think that's the best feeling so far. 

WTA Insider: Once again you've played a great final. For a player who says confidence does not come naturally to you, what is it about finals that you're just able to play a great one and be able to pull it back against the World No.1. 

Bertens: I think the feeling is you only have to play like one more match. You can give everything and the finish line is there. You know you can give everything you can and rest as much as you want afterwards. That mentality that you just keep on going, whatever is happening, even when you're matchpoint down, I think that's just what's really in me.

"When you really feel the ball it's nice if you can play winners from everywhere. But still, if I don't feel the ball so well on clay I still have another option and on the hardcourt, you don't have that so much." 

- Kiki Bertens

WTA Insider: When we had asked you earlier this week - what is it about Kiki Bertens that now she's not just a clay court specialist she's an all court specialist and you can win on all surfaces - you said the the fitness work, that you did the hellish off season that you that you spent in the offseason getting things shored up, and then also being more aggressive. 

So starting with the aggressiveness and how your game has changed. Has it changed also on clay or is this more something that you employ only on the faster surfaces, knowing that you have to step out of my comfort zone to play this way?

Bertens: I think also on clay I played a little bit more aggressive, like in my match against Caroline [Wozniacki] in Madrid. I played really aggressive but sometimes you have to do that. When you really feel the ball it's nice if you can play winners from everywhere. But still, if I don't feel the ball so well on clay I still have another option and on the hardcourt, you don't have that so much. 

We put just so much work into my serve, into the returns, in just the first and the second ball after that. It's really paying off right now.  

WTA Insider: Is it becoming more natural for you to play that way? 

Bertens: It's getting easier because I've done it so many times. But when we're playing exercises and I really have to hit the ball, Raemon's says after five times, Okay but now you really have to hit it. It's still a part of me that's not going like a hundred percent. It's always a little less but we're getting there.  

"In tennis, almost every week you're losing and if you're winning a title, which is great, then there's always the next day, you fly to another tournament and you play another tournament again. So it's all starting again and those were the moments where I could not really enjoy the wins."

- Kiki Bertens

WTA Insider: I think that in order for fans and for other people to really appreciate what you're doing right now, I think they do need to kind of understand how rough it was at the end of last season for you. 

Bertens: Yeah it was a really tough year last year. Of course I had some great results, but I was not feeling really happy on the court, not feeling really happy on the tour. At the end of the year it was just too much. Of course we made the finals in doubles in Singapore which was unbelievable, but still I needed some "me time" to think about, like, OK do I want to continue like this? I don't want that, being so stressed all the time, not enjoying my life, not not enjoying the life on tour, not even enjoying my wins. 

So I had to change something and that's what I thought about like on my holiday. I really needed some time, which was really good talking a lot with my boyfriend about it and just writing things down. I spoke to Raemon after that and he was willing to change also some things and to put all the hard work again in there with me. I'm glad he wanted to still be with me. 

And now we're here, so I think it's all working. It was all worth it. I'm enjoying my life right now I'm enjoying the time on tour. I'm enjoying my wins and learn from my losses. So it was just a great lesson.

WTA Insider: A lot of people look from the outside at the life of a pro tennis player and they would probably say how could you not enjoy this? How could that not be fun? I know that it's hard and there are moments where it is very, very difficult. What was it that made it not fun for you or not enjoyable? 

Bertens: It's just really tough. In tennis, almost every week you're losing and if you're winning a title, which is great, then there's always the next day you fly to another tournament and you play another tournament again. So it's all starting again and those were the moments where I could not really enjoy the wins. If you had a title it was just OK. You have to keep on going. You have to win again next week or it's another match again. And it was just like too much instead of enjoying just a moment.
I think that's what I'm more doing right now. Just take it day by day. Enjoy your win. And then tomorrow is just another day. You try to work as hard as you can again and if you lose okay then there's another week again. So it's more just simple thinking I'm doing right now. 

WTA Insider: Was there any part of you that thought last fall, 'No, there's more. I can do more. There's more that I want to do in this sport and I think I can.' Is that something that motivated you to kind of retool things with Raemon and start anew in this season. 

Bertens: I just wanted to try. Like OK, if I tried with a different perspective, if I work more on my fitness, if I'm going to work more on something else, I'm going to try to be more relaxed. Then if that's not working, OK. I tried everything and then I can say with a good feeling, Okay I tried everything but that was it. I didn't have that moment then. It was still, like, OK you can still achieve something in another way and let's try it. And you can always stop still so....  

WTA Insider: Well don't stop anytime soon. 

Bertens: No, no, no.

WTA Insider: Last question that I have for you that I have to ask: Kiki, do you love hardcourts? 

Bertens: I'm getting there. I'm getting close. It's not as much as the clay, but for now I have to say I really like it.