Grand Slam champions Serena Williams, Maria Sharapova, Petra Kvitova, Na Li, Franesca Schiavone, Svetlana Kuznetsova, Roger Federer, Juan Martin del Potro and Rafael Nadal will all be in action on Day Two of the Western & Southern Open.

 

Thirteen-time Grand Slam champion and the Toronto and Stanford winner this summer, Serena Williams opens her Cincinnati campaign unseeded against Barcelona runner-up Lucie Hradecka on Center Court.

 

Williams, who returned to action during the grass court season earlier this summer after a year-long injury layoff, earned her best Cincinnati result in ’06 when she advanced to the semifinals.

 

Last year’s Cincinnati finalist Sharapova, a three-time Grand Slam titlist, comes to the tournament this year after a runner-up showing at Wimbledon. In her first round, she’ll meet three-time Tour doubles winner Anastasia Rodionova in a night match on Center Court.

 

Petra Kvitova, who defeated Sharapova to win her first major title at Wimbledon this year, faces Russia’s Chanelle Scheepers on Court 3 at night, too. Scheepers, ranked No. 101 in the world, recently upset World No. 39 Rebecca Marino of Canada.

 

Another Grand Slam titlist in 2011, French Open champion Na Li opens play on Center Court against four-time Tour winner Lucie Safarova.

 

On the men’s side, 2010 Cincinnati champion Federer takes on Juan Martin del Potro. The two will battle it out on Center Court in the second night match in a rematch of the ’09 US Open, which del Potro won.

 

With the victory, the Argentine broke the stranglehold that Federer, 10-time Grand Slam champion Rafael Nadal and three-time Grand Slam champion Novak Djokovic kept on all major titles dating back to ’05.

 

In men’s doubles, 2011 Doha winners Nadal and partner Marc Lopez take on the Serbian duo of Montreal semifinalist Janko Tipsarevic and 2011 Sydney finalist Viktor Troicki.

 

In women’s doubles, 2010 French Open champion Schiavone and World No. 11 Andrea Petkovic takes on two-time Grand Slam winner Kuznetsova and No. 20 Julia Goerges.

 

In other notable singles matches, Montreal semifinalist Jo-Wilfried Tsonga takes on former World No. 9 Marin Cilic of Croatia, ’06 Cincinnati finalist James Blake meets French Open quarterfinalist Fabio Fognini and former world No. 1 Jelena Jankovic plays against two-time Tour titlist Iveta Benesova.