Defending champion Petra Kvitova was upset by qualifier and Czech compatriot Lucie Hradecka 6-4 6-3 in the second round of the Madrid Open on Wednesday.
Chinese number eight seed Li Na had to work hard on Wednesday before beating German Angelique Kerber 7-5, 6-4 in the last 16 of the Madrid Open.
World number one Novak Djokovic lashed out at Madrid Open organisers and the ATP over the event's controversial blue clay courts after fighting off Spanish qualifier Daniel Gimeno-Traver 6-2 2-6 6-3 in the second round on Tuesday.
Top seeds Victoria Azarenka and Maria Sharapova breezed past Czech opponents into the Madrid Open third round on Tuesday along with former world number one Serena Williams.
Victoria Azarenka will arrive for the London Olympics with her eyes on a gold medal rather than swapping pins.
A two-week break following the death of his grandfather has allowed Novak Djokovic to regain his focus in time to defend his Madrid Open title this week, the world number one said on Monday.
China's Li Na sailed to the third round of the Mutua Madrid Open on Monday night after clinching a comfortable 6-3, 6-1 win over Silvia Soler-Espinosa.
Serena Williams marked her first European appearance of the season with victory on the Madrid Open's striking blue clay courts on Monday, but her sister Venus crashed out in the second round.
In fine fettle after a month-long rest, Roger Federer is ready to get his clay season underway and continue his bid to recapture the world number one ranking from Novak Djokovic.
Spanish number one tennis player Rafael Nadal this Sunday highlighted the importance to him of the Mutua Madrid Open which is being played in Madrid this week.
The Madrid Mutual Tennis tournament was officially presented to the press this Thursday.
Rafa Nadal became the first player in the open era to win two tournaments seven times when he fought off tenacious Spanish compatriot David Ferrer 7-6 7-5 to win a thrilling Barcelona Open final on Sunday.