Isner, 29, fired 42 aces while falling 7-6 (7-4), 4-6, 7-6 (7-2), 7-6 (7-4) to Philipp Kohlschreiber of Germany. It’s the second straight year -- and only the second time in the tournament’s 134-year history -- that no American man reached the fourth round of the season’s final Grand Slam.
Isner, who has been eliminated by Kohlschreiber in the third round of each of the last three U.S. Opens, was ousted despite never losing his serve in 54 games during this year’s tournament.
Earlier in the day, No. 3 women’s seed Petra Kvitova was ousted by 145th-ranked Aleksandra Krunic. Just five of the women’s top 10 seeds remain in the draw, while none of the 10 highest seeded men have lost.
Canadian No. 7 seed Eugenie Bouchard continued her strong Grand Slam year with a 6-2, 6-7 (2-7), 6-4 win tonight against Barbora Zahlavova Strycova of the Czech Republic. Bouchard, 20, was a runner-up at Wimbledon after reaching the semifinals in the Australian and French opens.
Men’s No. 8 seed Andy Murray, the 2012 U.S. Open champion, won in four sets against Andrey Kuznetsov of Russia. Also advancing were No. 3 Stan Wawrinka of Switzerland and No. 9 Jo-Wilfried Tsonga of France.
Seeking her third straight U.S. Open title, Williams beat fellow American Varvara Lepchenko 6-3, 6-3 in Arthur Ashe Stadium, leaving her as the lone U.S. woman to reach the fourth round.
Playing in windy conditions at New York’s National Tennis Center, Lepchenko hit 10 more winners than Williams (24-14) but also had 11 more unforced errors (32-21).
“She really raised her game to an unbelievable level,” Williams said in a courtside interview after the 1-hour, 35-minute match. “I just tried to hang in there.”
Djokovic, who counts the 2011 U.S. Open among his seven Grand Slam titles, dominated Querrey of the U.S. in 1 hour, 25 minutes, winning 6-3, 6-2, 6-2.
“So far, so good,” Djokovic, who’s yet to drop a set in the tournament, said in a courtside interview. “All three rounds that I’ve played in the first week of the U.S. Open are no less than I wanted and expected.”
The 27-year-old Serbian reached the round of 16 for the eighth straight year at the U.S. Open and for the 22nd straight time in a Grand Slam. He’ll face No. 22 seed Kohlschreiber next.
Krunic, a 21-year-old qualifier from Serbia, began the week having never won a Grand Slam match. She finished it in the round of 16 after beating Kvitova, 24, of the Czech Republic, the reigning Wimbledon champion, 6-4, 6-4 in Louis Armstrong Stadium.
Krunic used her speed and court-coverage skills to extend several points against a more-experienced opponent. She let Kvitova force the action, hitting 17 winners compared to 33 for Kvitova.
“She played unbelievable tennis,” Kvitova said at a news conference. “She put a lot of balls back; almost all of them.”
Krunic made 14 unforced errors, while Kvitova had 34. The final point of the match was its longest rally -- 27 shots -- and ended with Krunic lying on her back after a Kvitova forehand missed its mark.
“It was an honor for me to be in the same court with Petra, as she’s a great champion,” Krunic said in a courtside interview. “I was hoping to win a set but I managed to win the match somehow. I don’t know how.”
Krunic’s fourth-round match will come against No. 16 seed Victoria Azarenka of Belarus, a runner-up at the last two U.S. Opens. Azarenka beat Russia’s Elena Vesnina 6-1, 6-1 in 57 minutes.
Murray, a Briton looking for his first tournament title this year, topped Kuznetsov 6-1, 7-5, 4-6, 6-2. He’ll face Tsonga, who won in straight sets against Pablo Carreno Busta of Spain.
Wawrinka, the 2014 Australian Open champion, advanced on a walkover when his third-round opponent, Slovenia’s Blaz Kavcic, withdrew with an injured right foot.
Italian No. 11 seed Flavia Pennetta beat American Nicole Gibbs 6-4, 6-0. She’ll next meet Australian No. 29 seed Casey Dellacqua, who eliminated Czech Karolina Pliskova 6-3, 3-6, 6-4.
Raonic’s next opponent will be 10th-seeded Kei Nishikori of Japan, who moved into the fourth round for the first time since 2008 by beating Leonardo Mayer of Argentina 6-4, 6-2, 6-3.
Closing out play tonight is Australian 19-year-old Nick Kyrgios, who will try to become the first teenager to reach the fourth round of the men’s draw since 2008, when 19-year-old Juan Martin del Potro was a quarterfinalist and Nishikori made the round of 16 at the age of 18.
Kyrgios will have his first meeting with Tommy Robredo of Spain, the No. 16 seed. Robredo, 32, had his best U.S. Open result last year, reaching the quarterfinals after knocking out Roger Federer.
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