Former number one Caroline Wozniacki rolled an ankle but battled on to post a 7-6 (9/7), 3-6, 6-4 opening win over Ksenia Pervak of Kazakhstan in the Madrid Masters on Sunday. The sixth-seeded Dane struggled on with her handicap to take victory in a match lasting more than three hours, saving an amazing 14 of the 22 break point she faced. The 2009 runner-up will now have time for her injury to heal before facing on-form German Mona Barthel, quarter-finalist a week ago in Stuttgart. Fourth seed Agnieszka Radwanska dismissed Spanish opposition with her defeat of Lara Arruabarrena-Vecino 6-3, 6-1 while 12th seeded Angelique Kerber of Germany started with a 6-1, 6-4 win over Swede Johanna Larsson. Belgian Yanina Wickmayer beat Australian Jarmila Gajdosova 6-2, 6-4 in 66 minutes despite 11 aces from the loser. Amid the controversy raging over the blue clay courts being trialled at this edition, Wozniacki had no complaints. "Blue is my favourite colour, this makes things a bit different," she said in the run-up to the French Open preliminary event at the Caja Magica. "The court seems a bit faster than when it was (traditional) red. "Adding the Madrid altitude (650 metres above sea level) makes it even faster. But we will only know who handled it best when the tournament is over." Defending champion Petra Kvitova, the third seed, rode her 2011 Madrid title over Victoria Azarenka to a breakthrough Wimbledon crown two months later. The Czech is back at this edition standing third in the world and hoping for a repeat of her previous success. "I haven't practised on them enough yet to say, but I think they are something new for us," she told the tournament website. "In my opinion they look very nice, very cool. "I like the colour, so I'm looking forward to playing on them."