Wimbledon 2011: Maria Sharapova wins in straight sets 
Maria Sharapova moved into the fourth round of Wimbledon with a 6-2 6-3 win over Klara Zakopalova that was tougher than the scoreline suggested.
An imperious first-set display by the 2004 champion underlined why many regard her as the favourite to lift the Venus Rosewater dish again this year.
But Sharapova briefly lost her way in the second before recovering strongly.
Top seed Caroline Wozniacki likewise made safe passage, beating Jarmila Gajdosova of Australia 6-3 6-2.
Sharapova will next play 20th seed Shuai Peng of China, who beat Melinda Czink 6-2 7-6.
Wozniacki will face Slovakia's Dominika Cibulkova, the 24th seed, who beat Julia Goerges 6-4 1-6 6-3.
"I haven't been past the fourth round for a few years so I am happy to get where I am," said the fifth-seeded Sharapova, who last progressed to week two in 2006, when she lost in the semi-finals to eventual champion Amelie Mauresmo.
"It's great to be in the second week. The opponents will get tougher but raising your level is what it's all about at the Grand Slams."
Sharapova was also relieved to make a better start than she had done against Britain's Laura Robson in the previous round. "I started slow against Laura," she said, "and I felt I had to be more aggressive today."
That spelled bad news for Zakopalova, who had beaten the Russian in their only previous meeting, in the first round of the 2003 Australian Open.
Unlike Serena Williams - who caused a minor furore earlier in the week by complaining that, as defending champion, she should not have been banished to an outside court for her second-round match with Simona Halep - Sharapova seemed to revel in the "intense" atmosphere of Court Two.
But having breezed through the first set in half an hour, the former champion was obliged to battle through a nine-minute opening service game at the start of the second.
That done, it seemed she would soon be making her way back through the crowded walkways of the All England Club to the locker room.
Zakopalova, the world number 35, faced two break points in the next game, and little she had done up to that point inspired confidence that her first foray beyond the opening round was destined for anything other than rapid curtailment.
Yet the 29-year-old, belatedly finding her range from the baseline, denied Sharapova with some heavy hitting before carving out a couple of openings against her opponent's delivery in the next game.
A heavy second serve from Sharapova saved one break point, but a double fault handed Zakopalova a vital break which she quickly consolidated to go 3-1 ahead.
The key moment came when Zakopalova held a point on serve for a 4-2 lead.
Sharapova, whose had become increasingly wayward off the ground as the second set unfolded, suddenly fired an off-forehand for a winner and the Czech, apparently unsettled, followed up with a double fault and an unforced error.
Zakopalova did not win another game, and Sharapova was left to contemplate a fourth-round meeting with Peng, who extended her to a third set on the hard courts of Indian Wells earlier this year.
"She's a really tough opponent on grass and she's playing some of her best tennis this year," said Sharapova of the world number 20.
Wozniacki expects a similarly testing time against Cibulkova. "It will be a tough one," she said. "She's a player that likes the courts fast. She takes the ball early and attacks, so for me it's important to get my serve in and play steady."
Elsewhere, 18th seed Ana Ivanovic was beaten 6-2 7-6 by Petra Cetkovska of the Czech Republic.
Cetkovskawill now face Germany's Sabine Lisicki, the world number 62, who followed up her surprise win over French Open champion Li Na by beating Misaki Doi 6-4 6-2.
Marion Bartoli,the 2007 finalist, battled back from the loss of the opening set to beat Italy's Flavia Pennetta 5-7 6-4 9-7.
Bartoli, seeded ninth, who saved three match points against Lourdes Dominguez Lino in the previous round, caused a stir at the end of the first set when she ordered her watching father to leave the court.
Monsieur Bartoli initially refused to comply, but eventually left when the umpire intervened. Next up for his daughter is Serena Williams, who won in straight sets against Maria Kirilenko on Court One .
