NEW YORK — The Latest on the U.S. Open tennis tournament (all times local):
The retractable roof on Arthur Ashe Stadium was closed because of light rain during the second set of defending U.S. Open champion Sloane Stephens' third-round match against Victoria Azarenka.
The match was delayed for less than 10 minutes.
Play continued on other courts without interruption, including the new Louis Armstrong Stadium, which has a retractable roof, too.
The $150 million Ashe roof was first used during the 2016 U.S. Open.
No. 15 seed Elise Mertens continued her breakthrough season by reaching the U.S. Open's fourth round with a 6-3, 7-6 (4) victory over No. 23 Barbora Strycova.
Mertens had never won a match at Flushing Meadows until this week.
The 22-year-old Belgian has now completed a full set of career-best showings at each Grand Slam tournament in 2018. She got to the semifinals at the Australian Open, the fourth round at the French Open and the third round at Wimbledon.
Mertens will next play Sloane Stephens or Victoria Azarenka.
The chair umpire who climbed out of his seat to talk with Nick Kyrgios during a second-round match will continue to officiate during the U.S. Open.
U.S. Tennis Association spokesman Chris Widmaier tells The Associated Press that a "comprehensive review conducted by a number of tournament officials" determined that chair umpire Mohamed Lahyani's mid-match chat with Kyrgios went "beyond our protocol."
But Widmaier said that Lahyani would not be sanctioned, on account of his "exemplary track record as an international tennis official."
Defending U.S. Open champions Rafael Nadal and Sloane Stephens are on the schedule for the third round at Flushing Meadows.
The No. 3-seeded Stephens begins the day session in Arthur Ashe Stadium on Friday by facing former No. 1 Victoria Azarenka, a two-time Australian Open champion and two-time finalist in New York.
That will be followed by the top-ranked Nadal's match against No. 27 Karen Khachanov of Russia.
The highlight of the night session in the main arena is the 30th tour-level matchup between Serena and Venus Williams. This is the earliest the sisters have played each other at a Grand Slam tournament since Venus beat Serena in the second round of the 1998 Australian Open, their first matchup as pros.