U.S. Open 2015: Serena beats Venus in battle of Williams sisters

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Serena Williams defeats older sister Venus

American chasing 22nd slam singles title

Men's champion Cilic to play Djokovic in semis

New York CNN  — 

It was the latest installment in the tennis battle everyone wanted to see: Serena vs. Venus.

As the Williams sisters faced off for the fifth time during their remarkable U.S. Open runs at Flushing Meadows, it was world No. 1 Serena who held off her big sister to win in three sets and book a place in the semifinals, continuing her bid for a calendar slam.

A visibly emotional Serena appeared to hold back tears before serving an ace to end the match, winning 6-2 1-6 6-3.

“It’s a really great moment, she’s the toughest player I’ve ever played in my life and the best person I know,” the defending champion said in an interview on court after the match.

“It’s going against your best friend, and at the same time going against the greatest competitor for me in women’s tennis. So it was really difficult today.”

Although Venus was the underdog going into the match, she challenged Serena’s dominance early on. After losing her serve twice in the first seven games to drop the first set, Venus came roaring back to win the second set after a slew of uncharacteristic Serena mistakes.

Ultimately, however, she could not keep up with the best player in the game right now.

“When I’m playing her I don’t think of her as my sister ‘cos she’s playing well, she’s hitting so many big serves and running a lot of balls down,” the younger Williams added. “When you’re in the moment you don’t really think about it.”

Epic battle

It was clear from the start that neither sister was in the mindset to ease up on the other, with Venus contesting line calls early on, and Serena clenching her fist and shrieking in celebration after breaking Venus in the fifth game.

Serena served 12 aces and committed 22 unforced errors to Venus’s eight aces and 15 unforced errors.

Her semifinal opponent is Italian Roberta Vinci, the world No. 43 who has not beaten her in four career attempts.

“She’s going to present a completely different game from my last four matches,” Williams said of the 32-year-old, who reached the first slam semifinal of her career by beating France’s Kristina Mladenovic in three sets earlier Tuesday. “She has nothing to lose, I don’t either, so we’re going to go out and have a lot of fun.”

Grand slam within reach

Williams is now only two victories away from completing her first career calendar grand slam, having won all three of the previous majors in 2015. No female player has achieved the feat since Steffi Graf in 1988, and no man has done it since Rod Laver in 1962.

She has already claimed a so-called “Serena Slam,” having won the last four majors in a row, and is on pace for one of the greatest runs ever in professional tennis.

Serena Williams celebrates after winning the quarterfinal match.

The feat is made even more remarkable by Serena playing her best tennis at what was considered an advanced age in the game. Her Wimbledon title in July broke the mark for the oldest singles victory in a grand slam tournament by a female at 33 years and 289 days.

Perhaps the most astounding statistic of all is the gap between Williams and world No. 2 Simona Halep in WTA point totals: Serena’s tally of 12,721 is more than double the Romanian’s 6,130. This, despite Serena playing two less tour matches over the past 52 weeks, not to mention the 10 more years of wear and tear on the courts over the 23-year-old, who plays former No. 1 Victoria Azarenka in Wednesday’s closing women’s quarterfinal.

A storied sibling rivalry

As professionals, the sisters first met in a grand slam – the second round of the 1998 Australian Open, with Venus winning in straight sets. Serena now holds a 16 -11 edge over Venus in overall competition.

But that hardly means playing Venus is a stress-free affair for the six-time U.S. Open champion.

“The only player in the draw I don’t want to play, not only because she’s my sister, but for me she’s the best player,” Serena said of Venus, a former No. 1 herself who is now ranked No. 23 in the world, ahead of Tuesday’s match.

“She has beaten me so many times,” added Serena, who has now won nine of their previous grand slam encounters and three out of five U.S. Open battles.

“She’s a player that knows how to win, knows how to beat me and knows my weaknesses better than anyone.”

READ: Beating Serena at a grand slam? Yes, it’s possible

Serena’s imposing game, force of will, and hunger have made the American especially difficult to stop at tennis’ four major tournaments, having a winning percentage of close to 90% in the grand slams.

“When she is in those events is where she really turns it on,” former world No. 4 Samantha Stosur told CNN.