The top-seeded pair of Coco Gauff and U.S. Open finalist Taylor Fritz of the United States are into the United Cup mixed teams tennis quarterfinals. Fritz beat Borna Coric 6-3, 6-2 Tuesday as the American team needed to win only one match to top Group A. For good measure, Gauff beat Donna Vekic 6-4, 6-2 in the later women’s singles. The U.S. beat Canada in its opening match.