MADRID — Maria Sharapova survived a sticky start to move into the second round of the WTA Madrid Open Monday with a 7-5, 6-2 win over Alexandra Dulgheru of Romania. The Russian, who won the French Open on clay last year, brought a 16-match winning streak on the surface into Madrid and was strongly favored to coast past a player who has been dogged by knee injuries. But she struggled at times in the first set before finding her range in the second. It had all been about adjusting to the dirt surface and the particular demands of playing in Madrid, Sharapova said. Milos Raonic said he needed to iron out “crucial mistakes” after the Canadian 12th seed squeaked past former world No. 3 Nikolay Davydenko 7- 7-6 in the men's section. Raonic, at 22 almost 10 years younger than his unseeded Russian opponent, managed one break of the Davydenko serve to secure the first set and edged the second-set tiebreak 7-5 to set up a second-round clash against unseeded Spaniard Fernando Verdasco, whom he has never beaten on clay in two attempts. Kei Nishikori joined Raonic in the second round when he thumped Austria's Jurgen Melzer 6-3, 6-2 as the Japanese 14th seed closes on a potential third-round meeting with world No. 2 Roger Federer. The stakes are high for Sharapova in Spain as she could regain the world No. 1 spot from Serena Williams if the results go her way. Williams won through in straight sets Sunday and the two could face off in the championship match at the end of the week. If Sharapova and Williams safely won through to the second round, the same could not be said of some of the other seeds. Both Caroline Wozniacki of Denmark and China's Li Na crashed out Sunday and Monday saw the end for Australia's Samnatha Stosur as she lost 7-6 (9/7), 6-2 to home hope Carla Suarez Navarro. Sixth seeded German Angelique Kerber came safely through with a 6-4, 6-2 win over Alize Cornet of France. “I feel like in the last week I've really had to adjust to the different circumstances and the environment a bit,” Sharapova said. “When I got here it was really cold and the ball and the court were really heavy. A few days have passed and it's like a whole ‘nother tournament. “For me, it's just been about adjusting when you play indoors for over a week and you get back here and see the sun for the first time. It's a bit of an adjustment.” Headbutt was defensive, says Tomic's dad The father of Australia's top-ranked tennis player Bernard Tomic said Monday he was acting in self-defense when he headbutted his son's training partner and broke his nose in Madrid. John Tomic denied a charge of assault against Thomas Drouet in a Saturday afternoon brawl outside a hotel where players in the Madrid Masters were staying, his lawyer Carmen Dieguez told journalists at a Madrid court. The court postponed a hearing to May 14 for a judge to decide his guilt or innocence after Tomic opted for court rather than paying a fine. “I don't feel guilty. I did not do anything wrong,” John Tomic told reporters of the fight, which has sparked consternation in the tennis world. John Tomic struck his son's training partner with his head only because his own arms were being held by Drouet and he had to protect himself from falling over, his lawyer said. If found guilty he could be sentenced to between three months and three years in prison. Drouet, who is from Monaco, appeared at the court house with a neck brace and white plaster over his nose. — Agencies