WASHINGTON (AP) — Top women's seed Simona Halep retired from her quarterfinal match at the Citi Open on Friday because of the heat, allowing Russia's Ekaterina Makarova to advance to the semifinals.

Halep, ranked second on the WTA Tour, retired trailing 1-0 in the third set after she and the seventh-seeded Makarova split the first two. Fourth-seeded German Julia Goerges beat sixth-seeded Monica Niculescu 6-3, 6-4, to advance.

On the men's side, eighth-seeded American Jack Sock defeated third-seeded Canadian Milos Raonic 7-5, 6-4 to reach the semifinals.

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