SERENA WILLIAMS BEAT defending champion Petra Kvitova 6-3, 7-5 today to reach the Wimbledon semi-finals for the eighth time.

In a match-up of the only two previous Wimbledon champions remaining in the women’s draw, Williams saved a set point when trailing 5-4 in the second and then broke Kvitova in the next game. She served out the match with the help of three aces and a service winner.

Williams broke once in each set and finished with 13 aces and 27 winners overall. On a start-and-stop day at Wimbledon, Andy Murray and Florian Mayer found enough time between rain showers to wrap up suspended matches and reach the quarter-finals.

David Ferrer also advanced on Centre Court, where organisers again came under scrutiny for their use of the retractable roof. Their decision to open and then close it caused the start of his match against Juan Martin del Potro to be delayed by about 40 minutes.

Murray made the last eight for the fifth straight year by beating the 16th-seeded Marin Cilic 7-5, 6-2, 6-3, while Mayer ousted Richard Gasquet of France 6-3, 6-1, 3-6, 6-2. American qualifier Brian Baker’s remarkable run ended with a 6-1, 7-6 (4), 6-3 loss to 27th-seeded Philipp Kohlschreiber of Germany.

Rain had prevented five of the men’s fourth-round matches from being completed Monday. The weather continued to cause headaches as the start of play on outside courts was delayed about 30 minutes because of light showers. When matches started, they were quickly halted again for another rain delay of about an hour.

“We stopped obviously a lot,” Murray said. “You’re always a little bit edgy when you come out after a rain delay when you have the momentum with you. You stop, and then you come back out, and it feels a bit like you start from scratch again. I needed to serve well today and I got a lot of free points that helped me out.”

Play on Centre Court didn’t even have time to start at all before the rain came. Organisers had closed the roof because of earlier showers in the morning but then decided to open it during a dry spell just before Ferrer’s match against del Potro was to start. When the showers then resumed, they promptly had to close it again and keep the players waiting.

Andy Murray of Britain reacts after defeating Marin Cilic of Croatia during a fourth round singles match today. (AP Photo/Kirsty Wigglesworth)

When the match began, Ferrer needed less than two hours to beat del Potro 6-3, 6-2, 6-3. Murray’s match was halted yesterday with the Briton leading 40-0 at 3-1 in the second set. He had time to play one point on Court 1 — clinching that game — before rain started falling again. One game later, the match was suspended once more. After the second resumption, there was another slight break early in the third set as the players remained in their chairs for about five minutes under umbrellas as officials waited for a light shower to subside.

The Briton’s victory never looked in doubt, though, and he served out the match to love when the Croat netted a backhand.

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