Sunday, First Round
 Caroline Wozniacki (DEN #10) vs. Yaroslava Shvedova (KAZ #38)
Head-to-head: first meeting
It has been an up and down start to 2013 for former World No.1 Caroline Wozniacki. Promising performances - notably a runner-up finish at Indian Wells - have been punctuated by the odd early loss, most recently to Carla Suárez Navarro last week in Stuttgart. The Dane's compact baseline game and superb movement make her a danger on the Madrid clay, although the draw has not been all that kind.
First up is the talented, if unpredictable, Yaroslava Shvedova. In Stuttgart, Shvedova ended a six-match losing streak with a run to the quarterfinals - including a victory over Wozniacki's conqueror, Suárez Navarro - and she certainly has the artillery in her heavy all-court game to pierce her opponent's watertight defenses and score the upset.
 Petra Kvitova (CZE #8) vs. Yanina Wickmayer (BEL #36)
Head-to-head: Kvitova leads 4-3
Two years ago Petra Kvitova began a silverware-laden second half of the season with victory in Madrid. In the opening months of 2013, she has shown signs that she could be ready to embark on a similar run.
However, the occasional bout of inconsistency still blights the Czech's game, a trait that is sure to encourage her opening foe, Yanina Wickmayer. Further encouragement for the Belgian comes in the form of her three career wins over Kvitova, although this is tempered by the fact that the last of these came over three years ago.
 Ana Ivanovic (SRB #16) vs. [Q] Bethanie Mattek-Sands (USA #72)
Head-to-head: Mattek-Sands leads 1-0
While Bethanie-Mattek Sands may be ranked well outside the Top 50, she is currently playing tennis befitting a player far higher up the tennis pyramid. The charismatic American has already notched up 23 wins this season, with six of these coming during a run through qualifying and into the semifinals at her most recent event, in Stuttgart.
Also enjoying a confidence-boosting week in Stuttgart was her first round opponent, Ana Ivanovic, who made the quarterfinals before being edged out over three sets by eventual champion Maria Sharapova. The only previous meeting between the two came at the same stage, at the same venue two years ago, with Mattek-Sands overcoming a nightmare start to win in three sets.
Around the grounds?
Serena Williams kicks off her title defense against feisty qualifier Yulia Putintseva, while elsewhere Agnieszka Radwanska and Li Na open their campaigns against Tamira Paszek and Tsvetana Pironkova, respectively.