2017 champion Sloane Stephens (left) knocked out in first round, Coco Gauff wins on debut
Sloane Stephens is out of the US Open in the first round, just two years after she won the championship.
Stephens, an American seeded No. 11, was stunned 6-3, 6-4 by Anna Kalinskaya, a 20-year-old Russian who is ranked 127th and never before had won a main-draw match at any Grand Slam tournament.
Stephens recently reunited with Kamau Murray, who coached her to the 2017 title at Flushing Meadows.
Her biggest problem was that her shots wouldn't go where she wanted: Stephens finished with 33 unforced errors, more than twice as many as Kalinskaya's 15.
Kalinskaya had been 0-5 at majors, 0-4 against top-20 opponents and never had appeared in a night match at a Slam.
GAUFF MOVES INTO ROUND 2
Coco Gauff has come back from a set and a break down to win her U.S. Open debut at age 15 by beating Anastasia Potapova 3-6, 6-2, 6-4.
Gauff got a wild-card entry from the US Tennis Association after making a surprising run to the fourth round at Wimbledon last month in the first Grand Slam tournament of her career.
The American fell behind 3-0 at the start against Potapova, an 18-year-old from Russia, then was broken to begin the second set and third before turning things around at Louis Armstrong Stadium.
The players' combined age of 33 made it the youngest matchup of the first round at Flushing Meadows.
