ATP roundup: U.S., Poland to clash in United Cup final

(Photo credit: Kirby Lee-Imagn Images)
Top-seeded United States and No. 2 seed Poland will meet Sunday in the United Cup final in Sydney.

Coco Gauff and Taylor Fritz topped the Czech team of Karolina Muchova and Tomas Machac on Saturday to advance. Gauff was a 6-1, 6-4 winner; Fritz took the victory when Machac, up a set at 7-6 (4), 5-6 abruptly retired.

Machac, serving at 5-5, lost serve in a love game to drop his thir