The Cincinnati Open has proven to be one of the most unpredictable WTA events in recent times.
No woman has defended her title since 2015, and since then there have been nine different champions over the past nine years.
As Coco Gauff looks to retain her title, we look back at the women who have won this event over the past decade.
After winning her first Cincinnati title in 2014, Williams made it back-to-back titles after triumphing in one of the most dominant seasons of her career.
In a rematch of the 2014 final, the top seed battled past Ana Ivanovic in the last eight before a convincing semi-final victory over Elina Svitolina.
That was followed by a 6-3, 7-6(5) victory in the final over Simona Halep, claiming the title after dropping just one set en route.
15th seed and future No 1 Pliskova served her way to one of the biggest titles of her career at the tournament eight years ago.
Pliskova did not drop a set on her way to the last eight, where she battled seventh seed Svetlana Kuznetsova in three sets before a comfortable semi-final victory over Garbine Muguruza.
The Czech then produced an equally dominant display in the final, dispatching Angelique Kerber 6-3, 6-1 for her first WTA 1000 title.
2017 – Garbine Muguruza
Fresh off winning the Wimbledon title, Spanish star Muguruza battled her way to the Cincinnati title in 2017.
After narrow victories over Madison Keys and Kuznetsova powered her into the last four, she downed Pliskova in a rematch of the 2016 semi-final to reach the championship match.
And, despite some tough matches early on, she stormed to victory, routing Halep 6-1, 6-0 for one of the biggest titles of her career.
2018 – Kiki Bertens
Unseeded Bertens defied the odds to claim one of the biggest titles of her career at the event six years ago.
The Dutch star beat second seed Caroline Wozniacki and fifth seed Svitolina on her way to the last four, where she rallied from a set down to defeat eighth seed Petra Kvitova.
And she pulled off another impressive comeback in the final, saving a championship point to beat Halep 2-6, 7-6(2), 6-2 and lift her first WTA 1000 crown.
Keys battled past the likes of Muguruza and fourth seed Halep to reach the last eight, where she convincingly dispatched Venus Williams before a semi-final win over Sofia Kenin.
The final against Kuznetsova was not easy but the American was able to get the job done in straight sets, winning 7-5, 7-6(5).
2020 – Victoria Azarenka
The 2020 edition was held in New York due to the COVID US Open bubble – but that did not stop 2013 champion Azarenka from reclaiming her title.
The former world No 1 eased past 15th seed Donna Vekic in round one and did not drop a set on her way to the last four, dispatching Ons Jabeur in the quarter-final.
Azarenka battled from a set down to defeat Johanna Konta in their semi-final, and then won the title after finalist Naomi Osaka was forced to withdraw due to injury.
2021 – Ashleigh Barty
Weeks after claiming her second major at SW19, Barty claimed her first and only Cincinnati title with an emphatic run through the draw.
The Australian dropped just two games against reigning champion Azarenka in round three, and then eased past ninth seed Barbora Krejcikova and Kerber to make the final.
Barty was a heavy favourite against surprise finalist Jill Teichmann and duly delivered, prevailing 6-3, 6-1 to lift the title.
2022 – Caroline Garcia
A stunning second half of 2022 saw former world No 4 Garcia storm to one of the biggest titles of her career two years ago.
Garcia came through qualifying and beat 4th seed Maria Sakkari in round two and seventh seed Jessica Pegula in the last eight, before a semi-final victory over sixth seed Aryna Sabalenka.
The French star then dispatched Kvitova 6-2, 6-4 to win the final and become the first qualifier to win a WTA 1000 title.
2023 – Coco Gauff
World No 2 Gauff comes in as the reigning champion after an epic run to her first, and currently only, WTA 1000 victory twelve months ago.
The seventh seed did not drop a set on her way to the last four, where she stunned Iga Swiatek in three sets – beating the world No 1 for the first time.
That powered her into the final, where she overcame Karolina Muchova 6-3, 6-4 to lift the title on home soil