By Lou Aguila (staff@latinospost.com) | First Posted: Apr 26, 2013 08:23 AM EDT

Top-seeds Maria Sharapova and Petra Kvitova advanced to the next round of the Porsche Grand Prix quarterfinals, though both had to overcome a gritty challenge from their respective opponents on the red dirt of Porsche Arena in Italy.

Sharapova, the defending champion and the no.1 seed in the tournament, had to endure three hours and nine minutes of competitive battle to dispatch Czech Republic's Lucie Safarova 6-4, 7-6, 6-3 in Thursday's second round battle.

Playing her first clay-court tournament of the season, the reigning French Open champion took a hard-fought opening set before succumbing to Safarova in a nerve-wracking tiebreaker in the second set.

But Sharapova recaptured her form in the decider as she came through with big shots to finally settle the score with Safarova.

"I've had a few three hour games in my career, so I knew I just had to keep fighting until the end," Sharapova told reporters after the game. "That's when it's the time to get the game-plan going and calm down a little bit," Sharapova told the Associated Press.

"Clay is one of her favorite surfaces and I knew this was going to be a tough game, so I am glad to get through. The first match of the clay-court season is always tough, it's nothing like practicing," she added.

With the victory, Safarova arranged a mouth-watering battle of the beauties match with Ana Ivanovic in the quarterfinals. Ivanovic booked her spot in the final eight with a 6-4, 6-3 win against Nadia Petrova of Russia.

Also surviving a tough second round contest was former Wimbledon Champion Petra Kvitova of Czech Republic.

The fifth-seeded Kvitova fought back from a one set deficit and then took the next two sets against Gorges to keep her title bid alive.

Li Na, another French Open winner, also cruised to the next round after defeating Croatia's Mirjana Lucic-Baroni 6-1,6-2 while no.3 seed Angelique Kerber pummeled Anastasia Pavlyuchenkova 6-0, 6-4.