NEW YORK (AP) Before they stepped on court, there was nothing to suggest Andy Murray would have any trouble against Adrian Mannarino in the U.S. Open's second round.
Murray, after all, is seeded No. 3, owns two major championships including at Flushing Meadows in 2012, and had reached at least the quarterfinals at the last 18 Grand Slam tournaments he'd entered. Mannarino, meanwhile, is ranked 35th, has never won a tour-level title, and only three times in his career has even managed to win more than one match at a major.
So it certainly came as a surprise when, in Thursday's very first game in Arthur Ashe Stadium, Mannarino broke Murray. About an hour later, Mannarino slammed an overhead winner to grab the first set. And 45 minutes after that, a serve-and-volley winner gave the Frenchman the second set, too.
Murray is nothing if not resilient, though. Despite looking as if he might be ready to wilt on another steamy day at Flushing Meadows - two more mid-match retirements, including by 28th-seeded Jack Sock of the United States, raised the total to 12 in the men's draw so far - Murray put together his eighth career comeback from a two-set deficit and beat Mannarino 5-7, 4-6, 6-1, 6-3, 6-1.
It gave Murray his 35th consecutive victory in a second-round Grand Slam match.
Mannarino, a lefty, delivered 12 of the match's first 14 forehand winners and repeatedly found success with drop shots. But his play eventually dipped, while Murray really cleaned up his own act after the rough start: He went from making 21 unforced errors in the first two sets to only 14 the rest of the way.
Early in the fourth set, Murray doubled over and rested his hands on his knees after a couple of points, the sort of thing the Brit has been known to do during matches - appearing weary or injured yet able to still play well. With his mother, British Fed Cup captain Judy, standing to clap and yell in the stands, Murray overcame whatever was troubling him to improve to 37-4 since getting married in April.
Sock took the opening two sets against 107th-ranked Ruben Bemelmans of Belgium and was three games away from winning in the third, but his body seized up because of cramps, unable to deal with the heat that topped 90 degrees (32 Celsius).
In a scary scene early in the fourth set, less than two hours in, Sock froze in place, his legs locked. A trainer helped the 22-year-old American sit down near the baseline, and Sock appeared to have trouble even extending his arm when Bemelmans walked around the net and leaned over for a handshake.
How bad was the heat?
''I didn't have too much difficulty,'' said Bemelmans, who will face French Open champion Stan Wawrinka next.
Sock didn't hold a news conference, instead releasing a statement via the U.S. Tennis Association that called his retirement ''extremely disappointing.''
Denis Istomin of Uzbekistan stopped playing against 20th-seeded Dominic Thiem of Austria, although no reason was immediately given. Including two retirements by women, 14 players have stopped playing during matches because of injury or illness, tying the 2011 U.S. Open for the most through the first two rounds at a Grand Slam tournament.
''Maybe it's the end of the year - players are not as fit ... as in the beginning of the year,'' Bemelmans said. ''It's the humidity, the heat - it's all these combinations.''
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