Williams sisters will meet in quarterfinals at U.S. Open

NEW YORK – No need for any extra practice for Serena Williams after this performance.

Plus, it’s not as if she needs to study too hard to figure out how to deal with her next opponent.

Playing far better than she did earlier in the U.S. Open as she chases a calendar-year Grand Slam, Williams set up a quarterfinal against older sister Venus with a 6-3, 6-3 victory over 19th-seeded Madison Keys on Sunday.

“A Williams will be in the semis, so that’s good,” the No. 1-seeded Serena said after needing only 68 minutes to dismiss Keys, a 20-year-old American with formidable serves and forehands who simply was outplayed.

Already a winner of the past four major tournaments, including last year’s U.S. Open, Serena is trying to become the first tennis player to win all four Grand Slam titles in the same season since Steffi Graf in 1988.

Venus, at 35 the oldest woman to enter the field, was on court even less time than her sibling, overwhelming 19-year-old qualifier Anett Kontaveit of Estonia 6-2, 6-1.

Venus’ match came first in Arthur Ashe Stadium, so then she had to decide whether to watch Serena play.

“I get very nervous, because even if I have to play Serena, I still want her to win, so I have a hard time watching unless she’s winning. Then it’s easy to watch,” said Venus, who won U.S. Open titles in 2000 and 2001, but had lost in the third round or earlier each of the past four years. “So it depends on how my nerves are.”

Serena acknowledged having a bout with the jitters before her second-round match, when she double-faulted 10 times, made another two dozen unforced errors and needed to come back over and over just to claim the opening set against a qualifier ranked 110th. Afterward, she took pointers from coach Patrick Mouratoglou and headed out to the practice court right away.

Then, in the third round, against someone ranked 101st, Serena dropped the first set and was two games from defeat in the second before turning things around. Again, she put in more work to fix things.

“I’m so proud that I was able to serve a lot better. Obviously I had to,” she said after winning 22 of 28 first-serve points and never facing a break point against Keys. “I was like, ‘Serena, it’s now or never. You’ve got to get that serve together.’ ”

Djokovic makes it 26

No. 1 Novak Djokovic is into his 26th straight major quarterfinal after a hard-fought victory over Roberto Bautista Agut.

Djokovic dropped a set for the first time this tournament, and the 23rd-seeded Spaniard made him work throughout the 6-3, 4-6, 6-4, 6-3 win Sunday night.

Bautista Agut, who has never reached a Grand Slam quarterfinal, was down a break in the second set. But he won the last four games to pull even, running down every shot, ripping big forehands and leaving Djokovic to stomp on his racket in disgust.

The nine-time major champ responded by raising his level to close out the match in four sets. He next faces 18th-seeded Feliciano Lopez, who is in a Grand Slam quarterfinal for the first time since 2011. Lopez defeated Fabio Fognini 6-3, 7-6 (5), 6-1 on Sunday.

Cilic overcomes injury

Defending champion Marin Cilic overcame a tweaked right ankle thanks in large part to 23 aces and returned to the quarterfinals with a 6-3, 2-6, 7-6 (2), 6-1 victory over 27th-seeded Jeremy Chardy of France.

Cilic smacked serves at up to 132 mph, relying on that big shot to carry him in the pivotal third-set tiebreaker. Cilic hit four serves in that tiebreaker and each one was an ace.

The ninth-seeded Croatian has won his past 11 matches at Flushing Meadows, where he reached his first Grand Slam final a year ago.

He rolled his ankle early in the second set but seemed to be moving fine by late in the third, which he ended with a down-the-line backhand passing winner on the run.

Bouchard out

Eugenie Bouchard withdrew from her fourth-round match because of a concussion.

The 25th-seeded Canadian was scheduled to face Roberta Vinci on Sunday. She slipped and fell in the U.S. Open locker room Friday.

On Saturday, she withdrew from two doubles matches but was still hoping to play singles. Tournament officials announced Sunday that she had a concussion and would not play.