NEW YORK (AP) — The Latest on the U.S. Open tennis tournament (all times local):
As one American star lost in the main draw Tuesday, another of the country's rising stars was on display at the U.S. Open.
Top-seeded junior Cori "Coco" Gauff won her second round match in straight sets, 6-2, 6-2, over Romanian Selma Stefania Cadar, before juniors matches were suspended because of the heat.
The 14-year-old comes into this tournament as the second-ranked junior in the world after winning the girls' French Open title earlier this year. She received a wild card into last year's U.S. Open and became the youngest player ever to make the girls' final.
Gauff's father, Corey, played basketball at Georgia State and her mother, Candi, ran track at Florida State.
Gauff said she tried both those sports, but found her niche with tennis.
Gauff received a wild card this year into the qualifiers for the main draw at Flushing Meadows, but lost 6-4, 6-1 to Heather Watson of England.
Defending champion Sloane Stephens has been knocked out of the U.S. Open in straight sets.
Anastasija Sevastova, the No. 19 seed, dominated Stephens 6-2, 6-3 to reach her first semifinal in Flushing Meadows after making it to the quarterfinals the past two years.
Stephens beat Sevastova a year ago on her way to the title, but had no answer for the Latvian on Tuesday.
Sevastova came into the match having broken her opponent's serve a tournament-leading 23 times. She broke Stephens twice in the opening set, including at love in the final game.
She broke again to go up 2-0 in the second set before Stephens, pleading with herself to fight, broke back.
But Sevastova broke again to go up 3-1.
She then dropped her racket and held her hands to her face as a Stephens shot went into the net on the match's final point.
The extreme heat policy is in effect for a second consecutive day at the U.S. Open.
A 10-minute break will be allowed between the second and third sets of women's singles matches if either player requests one. For men's singles matches, the break would come between the third and fourth sets.
The policy is a rule on the women's tour but not the men's. U.S. Open officials began putting it in play last week, when temperatures first soared into the mid-90s. The policy was in place Tuesday through Thursday.
It was 86 degrees just before the start of Tuesday's quarterfinal between Anastasija Sevastova and defending champion Sloane Stevens on Arthur Ashe Stadium, with temperatures again expected to rise through the 90s.
Serena Williams and Sloane Stephens can give the United States two U.S. Open semifinalists, a year after an all-American women's final four.
And for the first time since 2006, the host country can have a man there, too.
Williams and Stephens first have to win quarterfinal matches Tuesday. Defending champion Stephens is up first on Arthur Ashe Stadium, facing No. 19 seed Anastasija Sevastova in a rematch of Stephens' three-set victory in the same round at Flushing Meadows last year.
Williams, seeded 17th, meets the last player to beat her at the U.S. Open. Karolina Pliskova, the No. 8 seed, knocked off Williams in the 2016 semifinals before the 23-time Grand Slam champion missed last year's tournament, when she gave birth.
On the men's side, defending champion Rafael Nadal faces Dominic Thiem at night in a rematch of Nadal's French Open victory, and 2009 U.S. Open champion Juan Martin del Potro plays John Isner in the other quarterfinal.
If Isner wins, he would be the first American in the U.S. Open semifinals since Andy Roddick in 2006.
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