Caroline Wozniacki of Denmark celebrates after defeating Sara Errani of Italy in their women's singles quarterfinal match Tuesday. (Streeter Lecka / Getty Images)
New York — Caroline Wozniacki knew, as anyone paying attention does, that the woman she played in the U.S. Open quarterfinals, Sara Errani, does not hit booming serves.
And after noticing that Errani’s previous opponent, Mirjana Lucic-Baroni, tried unsuccessfully to pound those soft serves, Wozniacki decided the best course of action was simply to make sure she put those balls in play.
Getting all 34 of Errani’s serves back over the net, and then claiming 26 of those points, Wozniacki parlayed six breaks and a 26-12 total edge in winners into a 6-0, 6-1 victory over the 13th-seeded Errani in a wind-whipped match Tuesday night.
The victory for the 10th-seeded Wozniacki moved her into her first Grand Slam semifinal in three years.
“I learned quite a lot from Lucic the other day. She was going for every return and trying to make winners on every return,” Wozniacki said. “For me, that wasn’t really the game plan today. It was just putting pressure on her from the start, and kind of start the rally from there.”
Italy’s Errani averaged only 65 mph (105 kph) on second serves, and 78 mph (126 kph) on first serves, and that was a problem.
“I hoped she would miss something here and there,” said Errani, who beat Venus Williams in the third round, “but today she practically never missed.”
With the players’ towels and spectators’ napkins and all sorts of things being tossed around by the stirred-up air, Wozniacki dealt with the conditions far better than Errani. Although not right away.
The match began competitively enough, with a pair of points that lasted more than 20 strokes apiece in the first game. Errani earned four break points before 2009 U.S. Open runner-up Wozniacki eventually held despite a double-fault in which one serve didn’t come close to reaching the net.
“I have played in some very windy conditions here, but I know how to adapt,” said Wozniacki, the runner-up at the U.S. Open in 2009, and a semifinalist in 2011. “It just took me a few serves to kind of get into the rhythm and figure out where to throw the ball and what to aim for.”
Wozniacki, a former No. 1 who eliminated five-time major champion Maria Sharapova in three sets in the fourth round, will face unseeded Peng Shuai of China in the semifinals.
Errani was a finalist at the 2012 French Open, and made it to the final four at that year’s U.S. Open, too.
Federer advances to quarterfinals
Aside from a first-set blip, Roger Federerwas dominant in a 6-4, 6-3, 6-2 victory over 17th-seeded Roberto Bautista Agut that put the five-time champion in the U.S. Open quarterfinals for the 10th time in 11 years.
Federer was broken once, part of a three-game run for Bautista Agut that took the score from 5-1 to 5-4. But Federer, the second seed, had no trouble the second time he tried to serve out that set, which he ended with two aces.
Moving well and winning the point on 35 of 52 trips to the net, the second-seeded Federer needed less than two hours to improve to 25-1 in night matches at Arthur Ashe Stadium.
A year ago, Federer lost in the fourth round at Flushing Meadows. He will meet Gael Monfils.
Joining Federer in the quarterfinals is Tomas Berdych, who schooled Dominic Thiem in straight sets in the youngster’s debut in the round of 16.
The sixth-seed won 6-1, 6-2, 6-4 in 98 minutes, a day before Thiem’s 21st birthday. The 45th-ranked Berdych was the only unseeded man among the final 16.
Thiem had upset No. 11 Ernests Gulbis and No. 19 Feliciano Lopez in his fourth Grand Slam tournament. But he was overwhelmed by Berdych’s efficiency.
Thiem had 35 unforced errors and failed to convert all seven of his break points.
Berdych faces 14th-seeded Marin Cilic in the quarterfinals. Cilic edged No. 26 Gilles Simon, who was treated for a back problem early, 5-7, 7-6 (3), 6-4, 3-6, 6-3.
In earlier matches, Monfils took a surprisingly matter-of-fact 7-5, 7-6 (6), 7-5 victory in the fourth round over No. 7 Grigor Dimitrov.
There is a narrative building around No. 20 Monfils’ success this year at Flushing Meadows, where he hasn’t dropped a set en route to reaching the quarterfinals for the first time since 2010: He has matured, is playing more carefully and seriously.
Monfils rejected that notion after Tuesday’s win.
“I’m the same. So I will say I’m a bit more lucky than I was maybe sometime in the past. I think I haven’t changed a lot, to be honest. I haven’t changed a lot,” Monfils said. “I just play maybe solid today, but I’m still the same.”
In women’s quarterfinal action, 39th-ranked Peng Shuai ended the precocious run of 17-year-old Belinda Belic, 6-2, 6-1.
Peng, 28, advanced to her first Grand Slam semifinal in the 37th major tournament of her career; only five women took longer to get to the final four at one of the sport’s top four events.
Her voice choking with emotion during an on-court interview, Peng said she had pondered giving up pro tennis in the past, but “my coach, my parents — they always tell me to try to keep going and never ever, give up.”
Magical run ends
Tuesday also saw the end of the Open for CiCi Bellis.
A week after the 15-year-old Californian became the darling of the U.S. Open for pulling an upset, she was in a small room surrounded by a handful of reporters asking about her second-round loss — in the junior draw.
“I didn’t play as well as I wanted to, but that’s tennis,” she said. “I just have to move on.”
Bellis’ victory over Australian Open runner-up Dominika Cibulkova gave her made-in-a-minute stardom, a runaway Twitter feed and reporters from around the world calling her the future of American tennis.
Her loss in the second round to 48th-ranked Zarina Diyas, along with her latest loss as the top-seeded girl, brought her back to reality.
Men: 1 Novak Djokovic vs 8 Andy Murray, 3 Stan Wawrinka vs. 10 Kei Nishikori
Women: 1 Serena Williams vs. 11 Flavia Pennetta, 16 Victoria Azarenka vs. 17 Ekaterina Makarova