London: Serena Williams won the latest instalment of her rivalry with sister Venus as the world number one eased into the Wimbledon quarter-finals with a 6-4, 6-3 victory on Monday.
Serena, bidding for her sixth Wimbledon title, took just 67 minutes to see off Venus on Centre Court and will play Victoria Azarenka or Belinda Bencic for a place in the semi-finals.
The 33-year-old hit 36 winners and 10 aces to secure her 14th win in 26 meetings with her older sister, but it was clear neither sibling enjoyed the experience.
Venus Williams prepares to serve during her women's singles fourth round match against sister Serena on day seven of the 2015 Wimbledon Championships at The All England Tennis Club in Wimbledon, London, on Monday. Pic/AFP
"It's hard to feel excited about (beating) someone you root for all the time no matter what and you love so much and is your best friend in the world," Serena said. "It's never easy to play someone you love and care about.
"But I don't know how many more moments like this we'll have. I plan on playing for years but you never know if we'll have the opportunity to face each other. So I just took the moment in."
With the awkward family reunion out of the way, Serena can refocus on her bid to rewrite the history books.
The American, whose record for the year now stands at a remarkable 36-1, remains on course to become the first woman to win the French Open and Wimbledon back-to-back since she last achieved that feat in 2002. She is on a 25-match winning run at the majors, a blistering sequence that brought her the 2014 US Open crown and the Australian and French Open titles this year.
Serena will hold all four Grand Slam titles at the same time if she wins a sixth Wimbledon crown on Saturday. That would also leave the 20-time Grand Slam champion needing only to win the US Open in August to become the first woman since Steffi Graf in 1988 to land all four majors in the same year.
Venus, 35, and Serena have combined to win 27 Grand Slams, including five for each at Wimbledon. But, after regularly duelling for the sport's top prizes -- they have played in eight major finals -- this was only the third clash of the Williams clan in the last six years, their earliest ever at Wimbledon, and their first Grand Slam showdown since the 2009 Wimbledon final won by Serena.
So close off the court, to the extent that they shared a home in Florida until recently, the sisters have never hidden how uncomfortable they feel whenever they are forced to stand on opposing sides of the net. And following the pattern of their match-ups, which started 17 years ago in Australia, the usually volatile Serena was far less demonstrative than she had been when fighting back to beat Heather Watson in the previous round.
Even without the shrieks and fist-pumps, she still made a scintillating start, breaking to love in the opening game and taking the first eight points to established a quick 2-0 lead.
Venus finally got on the scoreboard in the third game and when she blasted a fierce winner to break back in the fourth game, it seemed Centre Court might be engaged by a real battle. But there were only occasional outbreaks of brilliance from the sisters, whose own lack of emotional engagement led to an equally subdued response from the crowd.
Serena produced most of them, breaking to go back ahead 3-2 and coasting through the rest of the set. That remained the pattern in the second set.
Although Venus twice staved off two break points, in the first and seventh games, she couldn't stem the tide forever and a ill-timed double fault gifted Serena a 4-3 lead that effectively ended the contest.
It was almost as if the sisters were relieved the ordeal was over as Serena barely celebrated before they quickly walked off court together.
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