Former US Open champion Samantha Stosur continued her buildup to the season's final grand slam with a convincing 6-1 7-5 win over Russia's Svetlana Kuznetsova in first round action at the Western and Southern Open on Monday.
The Australian 11th seed is among a host of former-grand slam winners making an appearance on the Cincinnati hardcourts this week, the joint event likely to be the final tune-up for the top players from both the WTA and ATP ahead of the US Open later this month.
American world number one Serena Williams, fresh off her win in Toronto, headlines a star studded women's field that will feature the top 20 ranked players.
The men's side of the draw is no less impressive with world number one Novak Djokovic, Wimbledon champion Andy Murray, Rafa Nadal, also a winner in Canada on Sunday, and Roger Federer taking centre stage.
With the top seeds receiving first round byes some of the bigger names will begin to ease into the action on Tuesday with Federer, seeking to add to his five Cincinnati titles, opening his account against Germany's Philipp Kohlschreiber.
On the women's side, world number three Maria Sharapova, healthy again after a lengthy injury layoff, returns to the court for the first time since Wimbledon against American Sloane Stephens.
The opening day of play on Monday saw plenty of upsets on the men's side with 13th seeded Spaniard Nicolas Almagro, number 14 Fabio Fognini of Italy and 16th seed Jerzey Janowicz of Poland all falling at the first hurdle.
Almagro was stopped 7-6 (3) 6-4 by Bulgarian Grigor Dimitrov while Czech Radek Stepanek dumped Fognini 6-2 6-4 and wildcard American James Blake eliminated Janowicz 6-1 7-5.
In contrast, all went according to script in women's action with ninth seeded German Angelique Kerber battling past Italian qualifier Karin Knapp 6-7(6) 6-0 6-1, while 12th seeded Roberta Vinci of Italy also needed three sets to see off American Bethanie Mattek-Sands 6-4 5-7 6-3.
Russian 16th seed Maria Kirilenko was a 4-6 7-6 (4) 7-6 (4) winner over Georgian Anna Tatishvili, while unseeded Venus Williams swept past Slovakia's Jana Cepelova 6-4 6-1 to the approval of the home crowd.
Swiss Martina Hingis continued her return to competition teaming up with Slovakian Daniela Hantuchova for a 4-6 6-4 10-5 first round doubles win over Spain's Anabel Medina Garrigues and Italian Flavia Pennetta.