CINCINNATI, Ohio - The Battle for No.1 heats up next week at the Western & Southern Open but the fireworks will start right off the bat. The main draw is out and the first round sees a blockbuster match, with Madison Keys and CoCo Vandeweghe locking horns in a rematch of the Bank of the West final.
Top 8 seeds: Karolina Pliskova, Simona Halep, Angelique Kerber, Garbiñe Muguruza, Elina Svitolina, Caroline Wozniacki, Johanna Konta, Svetlana Kuznetsova
Top half:  Pliskova,  Wozniacki,  Muguruza,  Kuznetsova
Bottom half: Halep,  Kerber,  Svitolina,  Konta
Projected quarterfinals: Pliskova vs. Wozniacki, Muguruza vs. Kuznetsova, Svitolina vs. Kerber, Konta vs. Halep.
Last year's final: Karolina Pliskova d. Angelique Kerber 6-3, 6-1.
What you need to know:
Karolina Pliskova's title defense will not be easy: Cincinnati is where it all started for Pliskova last year. After opting to skip the Olympics to focus on training, Pliskova rolled through the draw to beat Angelique Kerber in the final. She followed it up with a run to the US Open final and hasn't looked back. Twelve months on and she's the World No.1.
But will she leave Cincinnati with the No.1 ranking? Simona Halep is her primary challenger, though the number of players who could take the No.1 ranking in Cincinnati could grow depending on the results at the Rogers Cup. Pliskova's path to a title defense is a tough one. She could face Kristina Mladenovic in the third round and either Venus Williams or Caroline Wozniacki - who beat her last week at in the Toronto quarterfinals - in the quarterfinals. Looming in the semifinals could be No.4 seed Garbiñe Muguruza.
Simona Halep has the draw to chase down the No.1 ranking: The precise scenarios will become crystal clear at the conclusion of the Rogers Cup, but Halep will have yet another opportunity to get the No.1 ranking that she wants so badly. While Pliskova's top half of the draw is littered with in-form opposition, Halep's bottom half is slightly softer.
A semifinalist here last year, the first seed Halep could face is No.15 Anastasia Sevastova, with No.7 Johanna Konta or No.11 Dominika Cibulkova potentially in the quarterfinals, though CiCi Bellis and Ana Konjuh might have something to say about that. In the semifinals Halep could face either last year's runner-up Kerber, or a rock-solid No.5 Elina Svitolina. Also looming in Halep's half are Petra Kvitova and a resurgent Sloane Stephens.
The Battle for No.1 could expand beyond Pliskova and Halep: As many as five women could lead Cincinnati with the No.1 ranking, depending on their results at the Rogers Cup. Heading into the Toronto quarterfinals, Simona Halep, Garbiñe Muguruza, Caroline Wozniacki, and Elina Svitolina all have a mathematical chance of overtaking defending champion and No.1 Karolina Pliskova after Cincinnati. While Halep will have a shot no matter what she does in Toronto, Muguruza, Wozniacki, and Svitolina need to progress further in Canada to have a shot in Cincinnati.
Konta, Mladenovic, and Kerber, look for a kickstart: Johanna Konta, Kristina Mladenovic, Angelique Kerber, and Svetlana Kuznetsova didn't get much of a chance to get their hard court summers going last week in Canada. In her first match since the Wimbledon semifinals, Konta bowed out in three sets in her first match in Toronto to a streaking Ekaterina Makarova.
Mladenovic, who played a starring role through the first six months of the season is 7-7 since beating Muguruza at the French Open and has not won back-to-back matches since Birmingham. The World No.13, who chasing a Top 10 debut, is 1-2 on the summer hardcourts, losing the Bianca Andreescu in Washington D.C. and Barbora Strycova in Toronto.
Kerber looked to be finding her form at Wimbledon, where she narrowly lost to Muguruza in the Round of 16. But she looked completely out of sorts in a bad straight set loss to Stephens in Toronto. She'll be looking to find her footing and some confidence with her US Open title defense just two weeks away.
From Stanford final to Cincy first round: Madison Keys and CoCo Vandeweghe II: Madison Keys and CoCo Vandeweghe had never faced off before their showdown in the final of the Bank of the West Classic just a week ago, which Keys won 7-6(4), 6-4 to capture her first title of the season. Now they'll battle it out for the second time in three weeks, drawn to play each other in the first round in Cincinnati.
Keys-Vandeweghe isn't the only notable first round rematch. Sloane Stephens and Lucie Safarova, who played a hard-fought and top-quality quarterfinal in Toronto will play in the first round in Cincinnati, while Alizé Cornet will look to get revenge on young CiCi Bellis, who ousted her in the first round of Stanford. Also looking for revenge? Dominika Cibulkova, who will try and get the better of Ana Konjuh after the Croatian teen ousted her from Wimbledon in the third round.
Roland Garros champions face off in the first round: The large crowd on-hand for the on-site draw ceremony roared with excitement when two-time French Open champion Maria Sharapova was drawn to face reigning French Open champion Jelena Ostapenko in the first round in what will be their first ever meeting.
Ostapenko comes into Cincinnati on the heels of an opening round loss to Varvara Lepchenko in the Toronto, where the 20-year-old squandered a set and 3-0 lead. The questions about Sharapova again revolve around her fitness, as she was forced to withdraw after a first round win in Stanford with a left arm injury and opted not to play in Canada last week.
First round matches to watch: Madison Keys vs. CoCo Vandeweghe, Petra Kvitova vs. Anett Kontaveit, Kristina Mladenovic vs. Daria Gavrilova, Agnieszka Radwanska vs. Julia Goerges, Sloane Stephens vs. Lucie Safarova, Ekaterina Makarova vs. Barbora Strycova, CiCi Bellis vs. Alizé Cornet, Dominika Cibulkova vs. Ana Konjuh.
Main draw play begins on Monday.