NEW YORK — Serena Williams moved within three wins of achieving the fourth women’s calendar-year Grand Slam by routing fellow American Madison Keys on Sunday and setting up a U.S. Open quarterfinal clash with sister Venus.
Williams beat the 20-year-old Keys 6-3, 6-3 in 68 minutes to book a 27th professional career showdown with her older sister, who advanced with a 6-2, 6-1, 50-minute fourth-round victory over qualifier Anett Kontaveit, 19, of Estonia.
Three-time defending champion Serena holds a 15-11 advantage in the sisterly head-to-head series against Venus, splitting their four previous clashes at the U.S. Open.
“She’s playing great,” 33-year-old Serena said about seven-times grand slam winner Venus, who is two years her elder. “I have to really be ready for that.
“At least one of us, a Williams, will be in the semis.”
Top-seeded world number one Serena has won six of the last seven matches against Venus, who beat her younger sister last year in the semifinals in Montreal.
Venus was quick to identify her biggest challenge in facing Serena in Tuesday’s quarter-final.
“Well, obviously, that she’s so good. What else can you do except try to win the point and hope she doesn’t hit an ace,” Venus said.
Serena said it was always tough facing her sister.
“I’m playing, for me, the best player in the tournament, and that’s never easy,” she said. “She’s beaten me so many times … more than anybody.
“She’s a player that knows how to win, knows how to beat me, and knows my weaknesses better than anyone.
“So it’s not an easy match at all. Hopefully things will go right.”
Venus, whose last slam triumph came at the 2008 Wimbledon, said she thought she was playing well enough to win her third U.S. Open title. “Of course. I’d love to,” she said. “But it’s easier said than done.”
Serena brought her ‘A’ game against Keys, dropping just six points on serve in the first set.
Serena cracked six aces and never faced a break point in beating the power-hitting Keys, who put up a strong fight in their only previous meeting, in this year’s Australian Open semi-finals.
Keys lost 7-6(5), 6-2 in Melbourne, saving seven match points in the second set before succumbing.
This time, Serena played her strongest match of the tournament so far and Keys contributed to her loss.
In other action, defending champion Marin Cilic was the first man through to the quarterfinals, taking down determined Frenchman Jeremy Chardy 6-3, 2-6, 7-6(2), 6-1 to extend his Flushing Meadows win streak to 11 matches.
Coming off a punishing five-setter with Mikhail Kukushkin in a third-round match that lasted four hours, Cilic took a while to find his power game but was unstoppable once he did, the ninth seeded Croat blasting 23 aces past 27th seed Chardy, who had no answer.
“Key today was finding my rhythm on the serve, especially towards the end of the third set,” said Cilic. “I was having trouble a little with my movement after I twisted my ankle in the second set. That was causing me a little trouble, but in the end it’s pretty good.
“I played really good in the fourth set, really great tennis, so I’m happy about it.”
Cilic has found the defense of his title much tougher than winning, at least so far.
In last year’s march to the title, Cilic recorded straight set wins over Tomas Berdych in the quarters, Roger Federer in the semifinals and Kei Nishikori in the final.
This year, with the exception of a straight sets decision over Russian qualifier Evgeny Donskoy, all of Cilic’s matches have gone four sets or more.
After splitting the opening two sets, Cilic’s power began to show through particularly in the third set tiebreak when he used his big serve to full advantage firing four aces and going up 6-1 before closing out 7-2.
Cilic kept the pressure up, breaking the Frenchman in the fourth set, surging in front 5-0 and then serving out for the match.
In the late men’s match, No. 1 Novak Djokovic of Serbia beat 23rd seed Roberto Bautista of Spain 6-3, 4-6, 6-4, 6-3 to advance to the quarterfinals.