MADRID, Spain - Friday at the Mutua Madrid Open will see the semifinal line-up decided. First up is a rematch of last year's Roland Garros quarterfinal between Maria Sharapova and Kaia Kanepi, while over on Arantxa Sánchez-Vicario, Sara Errani meets Ekaterina Makarova and Angelique Kerber takes on Ana Ivanovic.
 Maria Sharapova (RUS #2) vs. Kaia Kanepi (EST #51)
Head-to-head: Sharapova leads 1-0
Good memories will come flooding back to Maria Sharapova when she steps out to face Kaia Kanepi on Manolo Santana. Last June, Sharapova outgunned Kanepi in their Roland Garros quarterfinal en route to completing her Career Slam.
Unfortunately for Kanepi, most signs point towards a similar outcome in the Spanish capital. Sharapova has picked up from where she left off in Paris, opening the clay court season with seven straight wins - taking her record on the surface over the past two years to 26-1 - and the defense of her Stuttgart title. Kanepi, meanwhile, is competing in just her fourth tournament since returning from a long-term Achilles injury, and her up and down performance levels suggests that she is still shaking off some of the match rustiness.
 Sara Errani (ITA #7) vs. Ekaterina Makarova (RUS #24)
Head-to-head: series tied 1-1
Any suggestions that Ekaterina Makarova might suffer a slight hangover after knocking out World No.3 Victoria Azarenka were dismissed in 89 efficient minutes on Thursday, as she brushed aside Marion Bartoli. The Russian will need to be similarly clinical in her next assignment, against the WTA's resident street fighter, Sara Errani.
With 28 wins this year - a number matched only by Serena Williams - Errani's tireless running, unerring consistency and underrated court craft has helped prove that her 2012 breakthrough was no fluke. Despite her clay court prowess, Errani has always struggled in Madrid's quick conditions, and her counterpunching game will need to be at its best to defuse Makarova's baseline arsenal.
 Angelique Kerber (GER #6) vs.  Ana Ivanovic (SRB #16)
Head-to-head: Ivanovic leads 2-0
Angelique Kerber's reward for her marathon third round win over Svetlana Kuznetsova is a meeting with another former French Open champion, Ana Ivanovic. Like Kerber, Ivanovic was also made to work for her last eight spot, overcoming a bout of the service yips and a 5-2 final set deficit to pip Laura Robson in a late-night thriller.
While her serve may have been misfiring, Ivanovic's trademark forehand has looked as impressive as ever in Madrid. If it continues to flow, she is certainly capable of finding a way through Kerber's watertight defenses, as she proved in their last encounter, which she won in straight sets during April's Germany-Serbia Fed Cup tie.
Also on court...
Defending champion Serena Williams opens up proceedings on Manolo Santana against Spain's Anabel Medina Garrigues, while in the doubles compatriots Carla Suárez Navarro and Sílvia Soler-Espinosa take on Cara Black and Marina Erakovic for a place in the final.