Women's champ Kvitova out MADRID — Rafael Nadal won his first match on the blue clay at the Madrid Open Wednesday, defeating Nikolay Davydenko 6-2, 6-2 in the second round. Nadal had little trouble on the surface that he criticized this week as soft and slippery, hitting six aces. “I played much better than I expect,” Nadal said. “The (blue) court ... doesn't make you feel comfortable. It's difficult, hard to attack and come back to defend. You just have to try and adapt.” In the women's tournament, defending champion Petra Kvitova lost to Lucie Hradecka 6-4, 6-3. Nadal, who broke his Russian opponent four times to advance to the third round, will next meet Fernando Verdasco. The Spaniard defeated Alejandro Falla of Colombia 6-7 (4), 6-4, 6-4. Third-ranked Roger Federer will play his opening match later Wednesday against Milos Raonic of Canada. Also, Marin Cilic beat John Isner 7-6 (4), 7-6 (3) and fifth-seeded David Ferrer advanced by beating Radek Stepanek 7-6 (4), 6-2. “It has nothing to do with the courts, I just didn't play well,” said Isner, who praised his Croatian opponent. “He has played better and he deserves to win.” Other men's winners Wednesday included Stanislas Wawrinka of Switzerland, Alexandr Dolgopolov of Russia and French pair Gael Monfils and Richard Gasquet. The third-seeded Kvitova struggled with her serve against Hradecka. Kvitova was broken five times by Hradecka of the Czech Republic, who will face Ekaterina Makarova in the third round. Makarova beat Maria Kirilenko of Russia 6-4, 6-4 to advance. World No. 1 Victoria Azarenka, who lost to Kvitova in last year's final of the premier clay event, claimed her place in the quarterfinals with a 6-4, 6-4 success against Ana Ivanovic of Serbia. Belarussian Azarenka, winner of four titles this year including her first Grand Slam singles at the Australian Open, needed four match points to finish off a stubborn Ivanovic and will play China's Li Na for a place in Friday's semifinals. Li, the French Open champion and eighth seed, beat 12th-seeded German Angelique Kerber 7-5 6-4. Ivanovic, who has never been past the second round in two previous appearances in the Spanish capital, made a strong start on the blue clay of the Manolo Santana show court and conjured an early break of the Azarenka serve. However, she tripped up at crucial moments during the remainder of the match and failed to convert three break points in the final game. Samantha Stosur of Australia, the fifth seed, also made it through to the last eight when she thrashed Czech Petra Cetkovska 6-3, 6-2 to set up a meeting with Hradecka or Russia's Ekaterina Makarova. Agnieszka Radwanska routed Sara Errani 6-0, 6-1 to advance. Errani failed to convert any of her eight break points as she showed little of the consistent play that carried her to three straight titles this season. Radwanska will next face Roberta Vinci following her 6-1, 6-2 victory over Yanina Wickmayer of Belgium. Ninth-seeded American Serena Williams, making her first appearance in Europe this year, plays her third-round match against fellow former No. 1 Caroline Wozniacki of Denmark, the sixth seed, Thursday.