Serena Williams to play Petra Kvitova in Wimbledon quarters

Serena Williams and Petra Kvitova were both made to work hard in their fourth-round matches on Monday before booking a Wimbledon quarter-final showdown.

Four-time champion Williams edged a 54-minute third set to win 6-1 2-6 7-5 against world number 65 Yaroslava Shvedova of Kazakhstan.

Defending champion Petra Kvitova came from a set down to beat Italy's Francesca Schiavone 4-6 7-5 6-1.

Elsewhere, Victoria Azarenka beat Ana Ivanovic in straight sets.

The world number three prevailed 6-1 6-0 and will meet Austrian Tamira Paszek for a place in the semi-finals.

Paszek, who put out former world number one Caroline Wozniacki, defeated Italian Roberta Vinci 6-2 6-2.

Sixth seed Williams, 30, raced through the first set in 29 minutes against Shvedova, who recorded the first-ever 'golden set' at a Grand Slam on Saturday.

But Shvedova answered with the second set in 34 minutes to set up a tantalising decider, which Williams edged to progress to a 12th Wimbledon quarter-final.

"As the tournament goes on and on, I tend to relax more and more and realize that this is a great opportunity for me," said Williams.

When asked about her chances of winning a fifth title, she responded: "I'm Serena Williams; I'm very confident."

The 22-year-old Kvitova wasted 10 break points in the first set as 2010 French Open champion Schiavone took the lead despite hitting only two winners.

Kvitova lost her serve again early in the second set in windy conditions on Court Three, but finally broke back for 2-2.

She clinched the set under a light rain and raced to a 5-0 lead before closing out the match in the third despite Schiavone's protests that play should have been stopped.

"The grass was a little bit humid so it was a little bit dangerous," said Kvitova. "But I was ready to play and to continue.

"I think it [Williams match] will be huge match for both of us, and I'm looking forward to playing against her. She is a great champion."