Caroline Wozniacki, of Denmark, returns a shot to Svetlana Kuznetsova, of Russia, during the second round of the U.S. Open tennis tournament, Wednesday, Aug. 31, 2016, in New York. (AP Photo/Seth Wenig)
NEW YORK (AP) The Latest on the U.S. Open (all times local):
Johanna Konta is back on court after collapsing during her U.S. Open second-round match.
Article continues below ...
The 13th-seeded Konta went down late in the second set Wednesday against Tsvetana Pironkova. As medical staff attended to her, she told them her heart started racing and she felt as though she was in shock. Temperatures were in the mid-80s on Wednesday.
After several minutes, Konta was able to stand up and walk to her chair. She went back on court and double-faulted to give the second set to Pironkova, then was taken to the locker room before the start of the third.
Konta won the first set 6-2 and was up a break in the second, which the 71st-ranked Pironkova went on to win 7-5.
Playing an opponent also coming off a five-set match, American John Isner advanced in four sets in the second round of the U.S. Open.
The 20th-seeded Isner beat Steve Darcis 6-3, 6-4, 6-7 (10), 6-3 in 2 hours, 54 minutes Wednesday. Both rallied from two sets down in the first round: Isner spent 3 hours, 27 minutes on court Monday, while Darcis needed 4 hours, 11 minutes.
Isner had a chance to close out the victory in the third-set tiebreaker but wasted four match points.
The 106th-ranked Darcis also faced the extra fatigue of going through qualifying to make the main draw.
Isner improved to 9-0 in U.S. Open second-round matches. He had 38 aces Wednesday, when he received treatment on his right knee and for blisters on his foot.
Two-time U.S. Open runner-up Caroline Wozniacki has defeated a top-10 opponent for the first time in nearly a year, bouncing back from a horrid start to beat 2004 champ Svetlana Kuznetsova.
The ninth-seeded Kuznetsova won the first four games of the match and was one point from going up 5-0. Then Wozniacki ran off seven straight games en route to a 6-4, 6-4 victory in the second round Wednesday.
Her ranking down to 74th after an ankle injury and on-court struggles, Wozniacki is unseeded at the U.S. Open for the first time since her debut in 2007. She had won two matches at the same tournament just once since early March.
It's Wozniacki's first trip to the third round at a major since Wimbledon last year.
Novak Djokovic will move on to the third round of the U.S. Open after his opponent withdrew before their match because of injury.
The top-ranked Djokovic faced a potentially tricky second-round matchup Wednesday against Jiri Vesely, who defeated him in their only meeting last spring. But Vesely pulled out of the tournament with left forearm inflammation a couple of hours before their match would have started.
The 2015 U.S. Open runner-up, Roberta Vinci, cruised into the third round for the sixth straight year.
The seventh-seeded Italian beat American Christina McHale 6-1, 6-3 on Wednesday. Vinci needed just 22 minutes to win the first set.
The 55th-ranked McHale was trying to reach the third round at the U.S. Open for the third time.
Vinci stunned Serena Williams in last year's semifinals to thwart her bid for the first Grand Slam since 1988, then lost to countrywoman Flavia Pennetta in the final.